Has anyone ever poured a concrete foundation by themselves before?  Looking to pour a 12x10 slab.  What materials and how much materials do i need ?

I have poured lots of concrete if you don't know what you are doing hire someone who does. Concrete is time sensitive and unforgiving if you screw it up it will never be right.

I agree.  This is not a large job and you maybe able to get somebody for a pretty good price as the season dies down.  If you can find someone who is recently retired or a contractor with good experience they could walk you through several steps to save money and just hire a couple of guys to check your work and finish it.

12'x10' is not that large, but it's huge if you've never finished concrete before.
If you're new to this, then hire someone and help them out if you want to learn and save a few bucks.

I'm a dedicated DIYer.  I'm all for doing things myself and do.  However, I don't do concrete work.  I've seen a bunch of DIYer concrete that was screwed up.  

Do yourself a favor and hire a concrete guy.  They will have all the equipment and experience to do the job right the first time.

You'll need about 1.5 tons of gravel and 1.75 yards of concrete for a 4 inch slab over 4 inches of gravel.  The actual concrete volume is around 1.5 yards but you don't want to be short if ordering from a plant.  Asking the plant to send an extra 1/4 or 1/2 yard is painfully expensive if you get a light load.  If you need to turn down the slab at the perimeter for walls and roof load etc, you'll need to add more concrete.

I wouldn't use anything less than 3,500 psi concrete, preferably, 4,000 psi.

If you do order the concrete from a plant tell them it's for an outdoor slab and you want 5 to 6 percent air content.  In addition, google "concrete bleed water" if you intend to use a smooth trowel finish.  Don't trap the bleed water under the surface....

Like the guys mentioned above,  hire someone to help if you can.

If you plan to hand mix some concrete, good luck, it isn't fun on a of slab that size.

confused here...

when you say "foundation" do you mean structural supporting walls replete with a footer?  
or are you only trying to do the "flatwork" part, namely a 12x10 slab?

in no case should you be DIY'ing a foundation.  there are simply too many issues facing you that require experience -- even more so since you are in NY and you need to will need to get the footer down below the frost line or you are going to suffer frost heave after just a couple of years.  

if it is just the flatwork, the actual concrete pour is about 1/4rd of the work.  initial preparation (including compaction, stone, moisture barrier, mesh reinforcement, forms, and pitch (to shed water) is about 1/2 the job.  then the pour.  and then 1/4 left to complete it with a desired surface finish and no concave (water holding) areas.  

without knowing what your end use is, and what the site looks like right now, i don't think anyone on ARFCOM can really provide good advice.  is it a repair job?  is it a virgin slab?  is it clay underneath?  can you get equipment to the site?  are you going to put a shed on it?  are you going to park an excavator on it?  does it need to be pitched for water runoff?  smooth finish or broom swept finish?  etc etc etc

in the trade, your job is referred to as "flatwork" -- slabs, driveways, sidewalks, etc.  flatwork is bread-and-butter stuff for a mason.  it's straightforward to bid, and after 25 jobs you have seen pretty much everything and can account for the usual pitfalls that crop up.  get some quotes.

ar-jedi

Don't do it yourself. At the very least, hire one or two guys who are experienced and have tools that will help you.

The original owner/builder of my current house poured his own foundation.  The basement slab had a 5.5" difference in elevation from low to high.

I knew when buying the place that I was going to redo that floor.

where i  ny? post in ht forum, somewhere there from Cortland does masonry work. He'll chime in.

Hire someone.

Just little things like overworking the surface can drive the stones deeper than you want resulting in spalling failure of the surface.

It has to be worked correctly and you only get one shot.