The book
Hamsterlopaedia has a good basic hamster genetics section in it
It was written in 2002 so there are some things that are a tad out of date, but the genetics and colours section is still pretty good.
The Midland Hamster Club also has a section on genetics on their website
here.
I'd also suggest popping along to a hamster show and chatting with some of the breeders there
There's not one that's really close to Brighton unfortunately, but there is one in Andover in June and one near Reading in September.