I divided my plot into 5 sections.
1 section (where I grow fruit) permanently.
3 sections of the plot are made up of 1.2m x 2.4m (4' x 8' in old money) raised beds. There are 12 of these in total and I rotate legumes, roots, brassicas and green manure in them. I don't have 2 raised beds next to each other that have the same family of crops either. As I grow organically (as much as possible) I try to prevent pest build up and spread.
The last section used to house hens (bantams). Next year I will be trying to grow some giant pumpkins in there.
I also have an area of the plot where I built compost bins out of old wooden pallets, a decked area (that used to have a shed on it until a storm ruined it), and 10 barrels for water.
I would suggest that you visit the plot with a tape measure, a pencil and some squared paper three times a day on a sunny day. First thing in the morning measure and draw your plot on the paper. Make a note of where the sun is on your paper (put a circle outside the boundary of your plot). Come back at mid-day and make a note of where the sun is again and do the same in the evening.
Plan your shed where it won't shade any of your plot (IE on the plot furthest away from where the sun is). Get some sort of water catchment set up now (next to the shed to catch run-off) to take advantage of winter rains. Build some compost bins (look up wooden pallet compost bins - very easy to build) before you start clearing your plot.
My biggest piece of advice that I can give is don't try and do it all at once. You can accomplish a lot over the winter and next year but I'll bet that you'll want to change something. It takes a few years to get to know your soil, improve it and to find out what will grow for you.
Oh - and have fun! Show us some pictures if you can.