is it better to disenchant a soulbound item and with whatever is left over sell it in the AH, or just sell it to a vender?  not really sure what to do. can anyone give me some help?

DISENCHANT. ususally what you get is worth more in the AH than what a vendor would have given you. also, that's how you get mats to do enchants with!

but me not being an enchanter can not have another player disenchant BoP items can i?

nope

I thought if you open a trade window & put the item to be disenchanted in the do not trade slot it could be done.

you can enchant  most items in the trade window  (except for like rings and a few others) however Disenchanting in the trade windows doesn't work.

if you are in an instance with a group, the general rule if no one wants the item is to let the enchanter have it. then they can disenchant it into something useful that isn't BOP and everyone in the group can roll on THAT. works out nicely.

Usually if you dis-enchant items the stuff you get will sell more on AH. And thats also how you get mats for Enchanting.