There are actually 2 train companies. WAGN goes from Cambridge to Kings Cross and is significantly faster (50 mins non stop service at peak times). One goes into Liverpool Street and takes longer (Fastest trains about 1h 15). This service does stop at Totteham Hale though, so you can get teh tube from tehir if it's easier for your office. Your annual season ticket can be bought from either company and used on both lines.
Ther aren't any straight through trains from stations North of Cambridge, though there are from some nice villages to the south, but that would mean your dh driving/bussing to work as well (which isn't impossible round the ring road, but isn't exactly quick) We are in great Shelford, which is very lovely, brilliant state primaries and takes 1h 23 minutes to Liverpool Street. Dh does it every day.
Within Cambridge itself, there is an area of v. nice houses around the station (Which is in teh South of teh city), Lyndewode, Tennison, Glisson roads. But it's a bit Fulhamesque - Rows of Town houses/Victorian villas facing onto the road, with long narrow gardens behind. And prices are similar as well - £600k for a nice 4/5 bed house. Hills Road has some v. nice houses, but we were put off by the fact it is a main road into Cambridge (albeit with a 30mph limit) and we figured if we were going to move out of London we may as well move to proper countryside. Good agents for the area are Bidwells, Savills and Tucker Gardner
On Schools - primary village schools seem to be v. good - and all have their own swimming pool! we are going private at Secondary so don't know anything about teh state sector then, but there are some excellent prvate schools in Cambridge (Perse for Girls was 2nd in National League tables) they are all based around the Hills Road/South City area.
If you have any more specific questions let me know - we are very happy to have made the move out, and dh is fine with the commute.