need information about areas of london, etc.

I am likely moving to London in Q3 of this year. However, I know nothing about the areas of London. I will be working near the Oxford Circus station. Can someone help me with good areas to live? I'd like to not have a commute of more than 45 min each way (I want to be able to see my kids). I'd also like to know the low range of prices one can expect for a 3 bedroom apartment (4 bedroom is a pipe dream).

We live in South London - the part is called Herne Hill and it's between Brixton and Dulwich.  Brixton is the last stop on the Victoria Line and it takes approximately 15 minutes to get to Oxford Circus.  Herne Hill does not have a tube station, but has a great overground train that takes you into Victoria in 10 minutes (which is two tube stops away from OC).  I really like Herne Hill - it's got a great park nearby some cute restaurants and is close enough to the bustle of Brixton without suffering any of the ill-effects.  However since you have children, I would suggest taking the plunge into Dulwich, which is similar to Herne Hill, a little further from Brixton, but more residential. 

There tends to be a huge divide between North of and South of the River here - my experience is South.

Good websites to check out are findaproperty.com, upmystreet.com and gumtree.com (good for private rentals/sales)

i used to live in Herne Hill... of all the places we lived while we were in London, that was my favourite.