I'm a hospital doc - respiratory and general medicine. Two kids, aged 4 and 9 months. Usually work 3 days a week, have varied days depending on hospital rotation and clinics etc. Love my job, miss my kids sometimes - but glad I have stuck it out as I think it gets easier once you can be (partly) your own boss - I start a consultant job in May and am going to be able to negotiate over days and hours of work etc. Some tips:
Be organised - have a Plan B and then a Plan C for childcare, but don't expect them always to work - and don't expect to get through your rotation without a few days off for childcare as sometimes mum is the only one who will do. I have always used nurseries - including hospital ones - but if I had to do it again would really consider childminder, expecially when they are little, and a nanny now that I have two kids.
Plan ahead - I would agree, let the deanery know your situation, and ask not to rotate too far away. Also DP not to go too far if possible - my DH works 90 mins drive away - not easy.
EWTD is to your advantage - I used to do a 1 in 4 and couldn't have survived with kids, but the rotas are better now. Ask for shift patterns that suit you - as long as you do the work, no-one minds swapping around to accomodate - better to talk to the rota organiser in advance. In my current job, I can't do lates on a Monday or Tuesday as DH has a clinic that always overruns, so I do all my lates towards the end of the week.
Ask DP to help! It is not your sole responsibility to do all the sorting out and worrying about childcare (although you're probably better at it) and even if he can do two pick ups or drop offs per week it takes the pressure off. Make sure that the housework is fairly split. Get a cleaner if possible. Lower your standards! (mine were already pretty low, TBH)
Don't pretend you don't have children - many of your bosses will have small children (and wives - ho hum) - and will understand the pressures. On the other hand, don't expect your colleagues without children to be super-interested. One of my colleagues was moaning yesterday morning that he was really, really tired after a night out - then he saw my 'I have been up all night with a baby with an ear infection and playing lego since 6am do not talk to me about being tired' look and graciously shut up. However, I try not to moan - I have chosen to work and have children, and if I'm not enjoying it then I could choose to do it differently, I think.
Seek out positive role models and ask for advice.
Do what is right for you and your family, not your bosses or the deanery or the rota organiser or even your colleagues.