Quoted: The house I bought this summer has a fireplace.  IIRC it has what's called a fireplace insert, whatever that is.  It's wood burning by the way and has an electric blower which circulates air into my family room.

Yes, it is called a fireplace insert. Now for some bad news. Chances are it is not installed properly. At least most of the ones I see in my area aren't. If it's just slide into the fireplace and doesn't have a properly sized liner, you have a fire hazard.

Best way I know how to explain it is to compare the scenerio to a fire hydrant, a fire hose and a tempature of 20 deg. F. If you have the nozzle completely open and connected to the fire hydrant, the water would be moving through the hose so fast it wouldn't have time to freeze inside the hose.

However, if you were to take that fire hose off the fire hydrant and manage to connect it to a water faucet off the side of your house, the water would be moving so slow through the fire hose that the water will start freezing around the inside edge of the fire hose.

All creosote is, is frozen smoke. It just freezes at a much higher tempature than water does. Think of smoke and creosote as steam and ice. Now think of the fireplace, without the insert, as the fire hydrant and the flue as the fire hose. When the stove was just slide in, the fire hydrant was replaced by a water faucet but the fire hose wasn't replaced with a garden hose.

I'd recommend that you see if you can't find a Certified Chimney Sweep to come inspect it for you. If they aren't certified I'd be leary. If you can't find one call the one as close to you as possible and ask them for recommendations in your area.

You can find a Certified Chimney Sweep here: www.csia.org

How do I know if it needs cleaned?

With a proper liner installed, which should be 8 inches (some times 6 inches) round, a 1/8th inch build up of creosote any where in the flue justifies sweeping.

If it doesn't have a proper liner, it's probably going to need sweeping. Even if it hasn't been used in years and doesn't have any creosote build up in the flue. What normally happens is that people don't have their chimney's swept until the fall. When they quite using them for the last time in the Spring, they just never have them swept again and all the creosote ends up falling off the flue walls and drop down onto the smoke shelf above the fire box and behind the damper, and on top of that stove. With all this creosote so close to so much heat, you have the potential to have a fire in an area of your chimney that wasn't designed to handle it.

Would also recommend a video scan of the inside of the flue and inspection of clearance to combustibles in the attic---I haven't seen a masonry chimney meet clearance to combustibles the whole seven years I've owned this business.

Is there any particular type of wood which is best?  There's an old tree in my backyard someone has already cut down and looks quite dry.  I assume it's fine to cut up into fire wood.

If you continue to use the wood stove, with a properly sized liner, I would only recommend hard woods that have been seasoned. The only way you're going to know if you have seasoned wood is if it's been cut, split, stacked off the ground, covered only on the top with the sides exposed and preferably facing south in a sunny area...for 6 months to a full year.

The tree in your back yard may be rotten. Rotten wood is just as bad to burn as green wood. It's got moisture content and the more moisture you have in your wood, the cooler your flue gases. The cooler your flue gases...more creosote (ice). This also includes the insects in the rotten wood. The POP's you'll be hearing are tiny little water bottles with legs.

Best advice on wood is, if you don't have it by the first week of April it's too late.

Now for masonry fireplace, not factory built fireplaces, the best wood to burn is...FREE WOOD!!! Seriously. If I had an open fireplace instead of a free standing stove, I would have no problem with burning pine in it. As long as it was properly seasoned. Only difference is, pine burns hotter and faster. This means that you don't put as much into the fireplace and you have to add wood to it more often. But it's good to have as back up if you don't think you'll have enough hard wood.

How do I prevent the fire from getting too hot?  Is there even such a thing as too hot a fire?

Yes there is such a thing as too hot a fire. If you get the fire too big the flames go further up into areas that weren't designed to have a fire take place in, i.e., the smoke chamber. Considering this is an area where creosote has formed, you've got plenty of fule to start a chimney fire.

To keep from having too big of a fire, only load the stove up about half way and see how it does. You should get a stove thermometer. They aren't accurate, but it will tell you when something abnormally is happening. Do a small fire first for a couple of hours and check the temp. The next day, do a medium fire and check the temp. After that, keep an eye on it if you see the needle raise above what a medium fire wood be.

If it's got glass doors, this helps to keep an eye on the flame...sometimes. Older stoves may have glass doors but they're useless if you don't want to clean them all the time. Newer stoves have a design that provides a hot air wash over the glass doors that keeps them clen.

What's the best way to start the fire?

A match.

Get a couple of pices of balled up news paper and place them in the center of the stove. Then place some small dry pieces, i.e., twigs, on top of the news paper. Have some somewhat larger pieces ready to go with the actually logs close behind them. As the small pieces start to burn good, add the larger pieces and repeat witht he logs.

After the logs are on, you may want to leave the door cracked open a little until the logs get to burning good. If you don't, the fire might not get enough oxygen and go out on you.

Any other advice (other than telling me to convert to gas ) anyone can give me?

You convert to gas I'll lock your account.

Read some other things in this thread that I'll respond to later. Right noe I got to get out the door to another appointment.

The house is 70yo with mostly original windows, so it is kind of drafty.

drafty is good...as far as fire is concerned.

fire is a combustion process that consumes oxygen and gives off all kinds of exhaust gases.

a house that 'breathes' a little is good thing, imo. you need the o2 as much as the fire does. new houses are built so darn airtight that most folks recommend venting in some fresh air supply when a fire is going in the fireplace.

i've owned several houses with conventional fireplaces and one with a heat-a-lator insert built into it. the conventional fire places gave off about as much heat as a gas cooking stove...very inefficient for heating. they were nice for looking at and that's about it.

the heat-a-lator was an improvement. this one was built into the fire box and had two blowers and two output registers.

Quoted: The house is 70yo with mostly original windows, so it is kind of drafty. drafty is good...as far as fire is concerned. fire is a combustion process that consumes oxygen and gives off all kinds of exhaust gases. a house that 'breathes' a little is good thing, imo. you need the o2 as much as the fire does. new houses are built so darn airtight that most folks recommend venting in some fresh air supply when a fire is going in the fireplace. i've owned several houses with conventional fireplaces and one with a heat-a-lator insert built into it. the conventional fire places gave off about as much heat as a gas cooking stove...very inefficient for heating. they were nice for looking at and that's about it. the heat-a-lator was an improvement. this one was built into the fire box and had two blowers and two output registers.

Most smoking problems can be solved by provided more make up air to the fireplace. Amazingly, some people just don't get it. They started building homes air tight to try and save on energy costs. Well they lowered energy consumption but created another problem in place of it. Homes so air tight are the reason we hear about the increase in CO poisionings and the air in our homes being more polluted than outside.

I've actually heard back to back radio commercials with one saying how great their homes are because they are sealed air tight and use less energy to heat and cool, then the next one stating the air in our homes are more polluted that outside and is why you should have an air filter in your home.

...those Heat-A-Lators can be a PITA!!! Especially those with heat exchanger tubes that run across the throat. Can't get the creosote off the smoke shelf on those.