Hello, my intention is to get out into the garden in the next few weeks, along with a friend and build a concrete base for a shed. 
If you have done this sort of thing before, can you share any tips or advice please? I've never undertaken anything like this before and would appreciate some help. I can't afford to hire a someone to do it for me, otherwise I would!
Also, can I do it even if it rains? Or does it need to be dry conditions? Thank you!