Hi,
Overstreet is the Bible and has tons of good info for reading about trends and getting good insight into the industry. That being said - it does not seem to be as accurate when it comes to really hot books. NO COMIC GUIDE SHOULD BE USED ALONE! In fact they are just guides - not absolutes. A great way to see what is going on with a particular book is to check EBAY "completed listings" on a regular basis. Books that didn't sell will show prices in red and books that actually did sell will show their prices in green. People can ask the moon for their stuff, but you want to know what the stuff is actually selling for.
Also - Nothing is more important when dealing with comics than accurate grading. Everyone wants to sell their stuff for as much as possible. The numbers jump significantly as the grades go up. With Chips there are really only a few grades - with comics they are broken down into at least 20 or 25 different grades. You cannot price a comic until you firmly understand the grading system. If you start selling and build a reputation as a bad grader you will get no repeat business. If you overgrade you will be getting lots of returns - If you undergrade you will be losing alot of money. I cannot stress enough that you will really need to understand grading.
Fell free to E-Mail me if you have any specific questions.
Don