Ok first things first - check, check and check again - spelling, grammar, punctuation ( that's how I weed out CV's initially). I've seen CV's from people with a bachelor's degree & 4-5 further professional qualifications with really basic errors - bin!
Don't worry about the short term, part time jobs (unless you are going for similar) - show the meaningful ones. At our age (I'm 43) employers are interested in the jobs that show progress in your career , not the filler (if the interviewer is sensible/professional). You can always put in a line stating "I have held several positions in retail & admin, mostly short term" if you feel you want to demonstrate work ethic and explain any gaps.
It can be useful to tailor your CV for each job - you can add & remove jobs/emphasis on jobs as need be, and match your CV to the position you are going for.
I think 10 yrs back is fine (unless something you did 15 yrs ago is relevant).
Also, in the current economic climate, I wouldn't judge anyone negatively for having moved jobs (unless it looked like they had quit a few times/never stuck anything serious for a decent amt of time - typically a yr)
Keep it short - 2 pages at most - interviewers may comment on this, but they won't read page 3 so will miss anything important on it!
Good clear font (I prefer Arial to Times New Roman) well spaced, good size too.
Bullet point the really important bits so they are easy to pick out and be specific on achievements e.g.
I have managed change successfully (generic)
Vs
I managed a team which had a 75% turnover in 8 months and productivity increased by 10% during the period of change.
There are some really good websites (on phone so can't link) - manager tools is good but is US so some of the work practices & employment legislation differ but the principles are good & lots of content is free.
I'll have a think & post more if I remember anything (after this glass of red maybe not)!
Best of luck!