I teach in post 16, so feel free to PM and ask any questions.
My college is technically FE, but really is much more like a sixth form. I teach academic subjects.
Things to watch out for: Lecturers do not necessarily get the same terms and conditions as teachers, so ask carefully about salary, holidays etc. I'm lucky, in my college my pay is as good as teachers, and I get the holidays too, but so many colleges don't.
There is a lot of pressure in FE /sixth forms for results. Every class you teach is likely to be an exam class, so you will be under pressure to get results, and will be held accountable for little johnny not passing his exams, or jane dropping out because she got pregnant. Everything is driven by success rates.
The other big thing is the marking. Again, because every class is an exam class, for me every piece of work submitted is an essay (that's how they're assessed in the exams) so there can be phenomenal amounts of marking, with no opportunities for flick and tick marking, or for an off the cuff lesson. I miss that from secondary teaching. Every lesson counts and has to be thoroughly prepared for. In secondary teaching, I used to know the books, and have a vague idea of what I wanted to teach and on the odd occasion, be able to wing it from my subject knowledge. You cannot wing it at A level, no matter how great your subject knowledge.
Finally, the last thing about post sixteen teaching is that it is often down to you to manage classroom behaviour. You don't tend to have detentions and the like for poor behaviour. Whilst behaviour tends not to be as bad, sometimes it would make life easier to have the back up that you get in schools.
However, on the upside, there is a lot less admin and stupid meetings compared to secondary. I also find that I have much greater autonomy in my teaching. I teach what I want to teach, so long as it meets the exam spec. Compared to when I taught in secondary, I am less required to be in all day every day, and I do not have all of the other commitments like detentions, parents evenings (only 2 a year, not 7+) etc...
Despite that, I love it. I personally think it is a great age to teach, and really feel as though I get to make a difference in the lives of the young people I work with. It is hard work, and the sector is under great pressure from underfunding. Again, this year, the govt has cut funding, so my hours have been cut, which means I will have teach more classes for the same money (in effect, I'll have yet another pay cut) and this has been going on (not all years) since 2007.