What do you mean?

Do you mean protecting stuff for the winter? or planting / sowing?

Is it heated?

Why not give it a good clean before it gets full! You could sow some lettuce (choose a winter one) or take cuttings from shrubs, Fuchsias and tender perennials. Make sure that it has an automatic window vent to open the window if the temp goes up. Invest in a max/min thermometer. It's no good knowing what the temp is as you look at it, you need to know how high or low it got. Has it got electricity? You'll need a fan heater if you want to keep the frost out. So, make a list and off to the garden centre! Or Xmas pressies or birthday?

Plant several pots of crocus bulbs. You can then enjoy the flowers early in the year when it is too miserable to spend much time looking at them in the garden.

This link might help;

http://www.thegardenersalmanac.co.uk/Greenhouse/September.htm

Thanks everyone for your advice, I had to clear it out it was full of stuff growing from the inside out and visa versa the glass etc is still pretty grubby so this weekend I shall give it a good wash anything I should use? or just washing up liquid. Wife likes the idea of crocus bulbs as the garden itself is all shrubs no flowers as such so I should imagine it will look a bit drab in the winter. Thanks again Duncan