Go to a metal detecting forum and read-lots.
Friendly Metal Detecting is a great resource.
I have a Fisher F2 and for the money it does extremely well. I have the 4" and 10" head and pin pointer. Pin pointer is crap but works. The big coil works good to about 10+ inches the smaller coil is great for shooting coins and working small lots. I also have a Black and Decker digging tool that has a sheath. It is pretty sturdy and is serrated on one side so it helps cutting sod plugs. You will need a dig tool.
Fisher F2 Review
Same guy on Vaction
I have found a mason jar of change, and some old odds and ends brass spigot ect. The F2 gives visual as well as sound so it helps to identity junk. you can filter certain frequencies but some of the frequencies that show Fe and Al can be gold. Gold sits very near Fe and if it is deep you will miss it. Ive dug a few silver coins but nothing special like Mercury dimes or walking Liberty quarters. To find the goods you have to dig. 9xs out of 10 it will be can slaw, tabs, nails, ect. I tie two bags to my belt, one for trash and the other for finds. I do not waste a lot of time looking at my finds I'll come home and wash them.
One really needs to define what you want to look for and where. Some models perform well in wet areas, some don't work at all in the wet. Beaches with heavy Fe sand will require a certain type of detector. If you plan on hunting/ prospecting gold you will want a different type too. In metal detection the adage the more you spend the better quality tool definitely comes into play. Cheap detectors will find stuff but they will miss stuff as well. I have read where folks will cover an area and have a buddy with better machine sweep the same path and find coins.
Good luck and happy hunting!
Edit: What every you buy, hit up one of the Vendors from Friendly Metal Detecting. They will in every way give you the best deal you can find. I got mine from Bart @
Big Boy Hobbies I do not normally shill for people, but Bart is straight up. I paid for mine and 2 days later it was at my house. He beat every price I could find and when I called he answered the phone.