Fossy old boy... the search is your friend. I would write out how to prep and spray your car like i usually do, but to be honest I have written it too many times now.
Try searching for 'prep', and 'respray' and you'll soon see many people are in the same boat as you and want to do a DIY spray. The more the merrier is what i say.... and for those reasons TMF has 'risen to the occassion' and supplied us users with a full 21 page 'step by step' guide telling you how to respray your beloved mini!

, going from the initial prep.. right through painting and ending with polishing etc.
This is all thanks to 'CooperShaz', who's given up god know's how many hours writing a guide

(actually...he probably comes on here to escape the missus or something

)
Anyway, Have a read though the guide, it's been permanently placed at the top of the Painting and Detailng section so that it's easy to find.
I will answer some of the questions, the others are answered in great detail in the guide:
**Don't use an electric sprayer. On pain of death

**Do it in a Gazebo.
**Whether you need a laquer or not depends on what kind of paint you use. Cellulose for instance doesn't require a laquer as it is cut back and buffed up to a Gloss finish (very laborious but can give excellent finish.) Other types will have what's called a Basecoat (colour) which cures to give a Matt finish, this then needs laquering over to give the mirror finish.
Mike.