PA work/secretarial

#1
as i've been temping here in the UK on and off between uni and travel as PA or medical secretary, i wonder if work of that nature, or temping work in general exists in BA and if it's even worth my while if i can teach.....although judging from the feedback i had to my thread about realistic earnings for tefl qualified teachers, unless you're based in an institute work can be sporadic and bitty throughout the working day.
so: does anyone have any eperience of temping work/agencies?
how much office/administrative jobs pay (also in light of the fact that i am bilingual in both languages to mother tongue standard) and are they silly hours/week? like 40+ as standard?
i just want to have an idea of what awaits me, as i don't want to have to scrimp and save over there.....essentially i want to avoid this as much as possible and save like mad in the coming months before arriving.