Cardio is important mate, so do that too. Keep it separate from your training, and on different days if you can. Having good stamina is useful when weight lifting, and essential on legs and major body parts.
Eat lots of the right foods for your body weight, and split your workout up into a major body part and a minor one per workout, giving legs their own day because these are very taxing on the body!
Find a good gym partner if you can, get a friend to get into it with you, and then use can work with each other, which is always nice. Helps keep you motivated too. Be careful though, I've been through loads and got sick of waiting around for them to turn up, only to get a text after sitting round the gym for half an hour to be told they're not coming.
Benni