When I was at university I experimented with the Moosewood Cookbook. It is a classic vegetarian cookbook; often it’s less expensive to experiment with legumes and vegetables than meats and seafood. I learnt to make pakora vegetables and great banana bread from it. But back then, though I loved to cook and entertain, I wasn’t into eating healthily as much as going to the pub and getting take away fish & chip’s every Friday night.
I suggest Julia Child’s The Way To Cookas it has great pictures that makes it easy to follow along. Also I really love using Mark Bittman’s How to Cook Everything now.
Best of luck!