Depends on the quality of your collection on how best to sell them.
Gauging condition is tricky but generally it's all about being as close to newly printed (mint) as possible - crisp, clean pages!
I'm not fussed about yellowed pages too much, but others are, so mention any yellowing and on which issues.
If you've stored them in a pile, are they creased or curled at the spine?
One thing I do have an issue with is if there are pages missing (cut out coupons, features, pin-ups or otherwise).
It is also worth mentioning any tears or other blemishes no matter how small, particularly on early issues.
Here IS a good place to start, if you post up a list of what you have in a new topic, and a realistic figure that you'd like for them, you'll get a few decent offers I think.
Otherwise, ebay is really the best place. Selling them as a job lot is easiest and will leave you with none to throw away... but I believe the way to realize the largest profit is sell each of the 1-10 issues individually then in batches of 5-10 up to prog100 and then in yearly or half yearly batches. This way people looking to fill out their collections will be more likely to bid... I reckon you'll definitely still end up with some left but you might get away with it if you start the bidding low enough and don't over-charge on postage.
I'm sure some would disagree with me, this is just how I would do it.
