Mory, I'm not a long-time seller, but I'll share with you what >I< do:
1) The first thing I do is an ebay search to see if what I'm thinking of selling is already being sold. If so,
2) Then I study the listings of a few of the items that are most similar to mine to get an idea of what my description should include and say.
3) I follow the similar items in their auctions to see what kind of bid action they get and final bid prices. Would I be happy with similar prices?
4) In listing, if you feel you don't know as much about the item as you'd like, admit right up front to that, and just describe the item to the BEST of your ability. Welcome questions.
5) Take some good pictures, similar to the ones you saw in similar listings.
That should at least get you started. I'm sure others on here can add lots of good tips!
Jabbergah