Posted: 09/10/2012 at 15:52
It clearly needs lots of TLC to get it fit to grow anything! Random thoughts in no particular order:
Do you have pets? Children? Factor their needs in. How much time do you want to spend in it? (will dictate annual versus perennial mix). Do you need a lawn? (you'll never get a decent one in shade) Assuming you don't spend the winter taking that up, digging it all over and adding as much compost/manure as you can. See where the sun falls (remembering it wil be different in summer). Test the soil. Look to see what you like that is growing in neighbouring gardens - it will do well in yours.
North facing is tricky for veg - I would start off with a small raised bed in the sunniest spot. Easy stuff - runner beans, lettuce, herbs etc.
Get the structure in first. Think about hard landscaping - paths, benches etc.
You won't get it 'right' first time - or even ever. It's a lifelong addiction - good luck!