Ram prices are low. Check your owners guide for information on the type of ram you need. You can check places like Tiger Direct, New Egg, etc for more ram.
"Once I talked to the inmates of an insane asylum in Hartford. I have talked to idiots a thousand times, but only once to the insane..." Mark Twain
I also recommend http://www.newegg.com, I use them all the time. As for what kind of memory to get, consult your computer's manual for the exact memory type you need. If that's not possible for some reason, then I'd suggest using a tool like CPU-Z (the Memory and SPD tabs) or memtest86 to find out what kind of memory you are running now. Some memory manufacturers like Crucial have tools you can use to identify your memory.
A very good article on memory types and configurartions is here:
