Am assuming you're thinking of Secondary teaching, pitchounette?
What subject might you teach?
In my experience this has a big impact on the kind of workload you get as a teacher.
e.g. I teach secondary drama which means that until the kids get to GCSE level there is very little written work (and therefore marking) required. This is very different if you teach, say, English, where all ages generate lots of marking all through the year.
However, Drama teachers have a lot of different kinds of pressures - e.g. doing school plays which invariably take over your life for approximately a month culminating with the performances at the end.
Also the level of variety is very much controlled by your subject e.g. the maths curriculum seems to rarely change much, whereas other subjects (e.g. art, drama, DT, more creative subjects) are usually more flexible.
So if you teach a subject where the curriculum is pretty much fixed you can end up just repeating the same old same old which might get dull but at least you aren't doing lesson prep. all the time. But if you're doing a subject that's less controlled by a fixed curriculum on one hand it's possibly more interesting but you also need to constantly generate new materials.