My twins are 7 now, but I went back to work full time when they were 4. It was fine. It's still fine. It helps that DH is really really supportive, and that their nursery was lovely, and that now, they have a fabulous breakfast club and after school club at their primary school.
I love my job. There is a lot of planning, and I am a dept of one (Performing Arts) so have to do all the exam classes and all the data and all the admin myself. However, I can use previous plans and tweak them for new groups, and have good systems in place to make my admin and data stuff manageable. My busiest time is now, as we do the school production in February. I've been in school all day today, but my kids came with me - they've done this for the last three year, and they really enjoy it. I give them little jobs to do, and they sit with me whilst I run the rehearsals. The older girls love looking after them and playing with them in breaks.
I see my kids every day - I take them to school and pick them up, then I focus on them until they are in bed. After that, I do work, except on Wednesdays when I have choir. I'm usually in bed at a reasonable hour (ie before 11) and make time for a bit of time with DH, even if we slob in front of the telly.
The key is to be really organised, and to realise that you can't do everything. Be efficient at school - I always leave meetings on time, and take my bags and coat with me so I can go straight from the meeting to the car.
If you want to make it work, then you can make it work. Good luck!