After taking over a 5 rod plot covered with couch grass (plus friends) in Feb 2005 and managing to work on just under half the area last year, the whole plot is now officially usable/cultivable. The produce from last year was great - tomatoes, courgettes, onions, garlic, potatoes, rocket, herbs! Maybe largely due to the fact that the plot had been unused for a couple of years.
So far in 2006 I've gone from excitement of planning this year's crops to vague disappointment because despite the fact that I've now cleared most of the weeds (for now!), it seems to be taking ages for anything to get going. Much slower & later than last year. Seeds I planted in March haven't germinated (e.g. parsnip) or show really poor growth (e.g. broad bean). I don't know if I should worry . . . I think I'm gonna keep planting and see what happens in May

One thing I've found very useful is keeping an allotment log - including photos, comments, dates & assorted titbits to keep me amused. 8)