If you're running windows open another cmd window and navigate back to the namecoin folder.
Than type 'namecoind getinfo' if your conf file is setup right you should see it spit out your address,balance, block count, etc.
As far as mining is concerened it's the 'same' as bitcoin. You just need to get you payout address (which may be a bit trickier)
To get a payout address from namecoind, just open another command prompt and type:
namecoind getaccountaddress ""
This will give you the address of the default account.
You can ask namecoind for another address by issuing the following command:
namecoind getnewaddress
If you want to see how many blocks are downloaded, just type:
namecoind getblockcount
If you like to get some more info than just the block count, maybe you can try:
namecoind getinfo
If you want to check the complete list of commands type:
namecoind help
With this you should be able to get started...