how do I figure out what an electronic board is worth?

I have been collecting various boards from different pieces of electronics that I scrapped. Basically, I have four piles:
1. computer motherboards
2. boards pulled from CRT monitors
3. boards from old tube TVs -- some are probably 15-20-25 years old -- and other non-computer electronics like boomboxes etc
4. PCI boards of various types like wireless cards etc
So how do I figure out whether they are worth anything? PCI cards all have gold fingers, so I guess that's good. But what about all the other types? Also, if I do try to sell them on ebay in bulk, do I have to first remove large components like capacitors? Do I cut up the bigger boards into pieces that are more valuable, or do I keep them intact?

Thanks!

Call an e-cycler. I get $1.80 a pound for motherboards. Boards in other things like cd players do not make as much. The cpu(central processing unit) in a computer. The main chip. Usually made by AMD or Intel go for between $30 and $40 dollars a pound here in Ontario. I haven't noticed any difference by cutting them. They actually recover Gold and Silver from the circuit boards.
Hope that helps.