To record while you're watching live TV, just hit the Rec button on the bottom left of the remote.

To record from the guide:

1. Hit the Guide button on your remote
2. Highlight the show you want to record by using the Up, Down, Left, Right navigational keys
3. Press the Rec button on the remote
4. You'll be asked if you'd like to record just this episode or the entire season - select the option you'd like and press OK to begin the recording 

To delete something you've recorded:

1. Press the Recordings button on the bottom right of your remote
2. Select the show in your library and press OK
3. Select the episode you want to delete, and press OK
4. You will be asked if you'd like to delete just this episode or all episodes you have saved, select the option you'd like and press OK