use cudaminer 2.3.2

register at pool website like wemineltc, login then add one worker id and password.

put the pool server's stratum server address and port into cudaminer bat file, your worker id and password. refer to cudaminer readme file or website for the command line.

don't forget to install litecoin wallet so you can transfer the litecoins from pool into your own wallet

which rate are you talking about? is it the card hashrate? or is it about how many coins u can get a day? or is it the current price?

The coins that you'll get per day is according to how much hashrate power u currently have, or in simpler terms, how much u have invested. Typically a 10k mining rig setup would get you around 20 LTC per month.

Difference between litecoin and bitcoin? Price, algorithm used, way of mining, market cap, logo etc. I suggest you to google more on this.