Congratulations and welcome!

My advice is to head down to the local library and check out a copy of the Scott Standard Postage Stamp Catalog (the A-B volume or the Specialized volume). Either of those volumes will help you identify the stamps you have and get a general idea as to value.
Keep in mind that the Scott catalog will not price a stamp at less than $0.20. Most US stamps printed after 1940 regularly sell for less than face value (as singles, anyway).
There are certain more desirable items you could look out for, but you will want to have a catalog to help you.
Please feel free to post scans here and/or ask questions.