First of all, welcome to the forum.
What wallet accepts namecoins?
You can use namecoin-client if you want to use your namecoins and it will be more secure or open an account at any exchanges like cryptsy.com , if you want to trade it.
What are they anyway?
Namecoin is an altcoin , it is an alternative for BTC.
Can they be converted to bitcoins? Help please.
Yes, it can be converted to BTC and other currencies. Use exchanges like cryptsy.com .
P.S. Some useful links:- Namecoin website : namecoin.info , announcement(ANN) on this forum :
https://bitcointalk.org/index.php?topic=236375.0 ~~MZ~~