Hi Sue:
As Stampgal said, you can put questions in the support areas. Or as a general rule, if you don't know where to ask, just post in the MAIN forum. Most "general" things end up there

You've more than met the 14/50 rules, so you should just jump in and get your feet wet.
Here are a couple things to consider:
1. If you have an item and you know you want $50 (or some set amount), list it in the SELL forum. If you want folks to bid, post it as an AUCTION
2. In your description, list what you know about the stamp(s).
3. Establish a specific end date/time within 7 days of your post. Some people use "SCF Time" since there are members in many time zones. SCF time is US-Eastern, by the way.
4. Post a good-quality scan of your stamp(s). Some bidders will want to see the back of the stamp also -- especially for more expensive stamps.
5. Specify what payments you will accept: PayPal, personal checks, etc.
6. Finally, be sure you address postage/shipping costs -- again, there are several international members here. It's OK to say, "buyer pays actual postage" for those far away from you.
Hope this helps,
Kirk
P.S. And this is just one of my personal observations -- update your SCF Profile so we can see if you're in USA or Egypt. It gives us an idea of what to expect in postage costs. For example, I can see below Dianne's name that she's in Canada, so I know a letter to her costs me 80 cents; Stampgal is in UK, so a letter to her is 98 cents.