What are the Halachot reagrding making Challah? i.e. How much is enough to separate for, and how much must be separated? Also when do i say a Bracha for it, and how much needs to be separated in order to make a Bracha?

In general terms, you would separate a small amount (Kazait) from the dough, say the Bracha as appears in the Siddur and burn it. The amount of flour that requires separation is: up to 1.25kg - no Challa needs to be separated, 1.25-2.25 kg - without a Bracha, over 2.25 kg - with a Bracha. The exact measurement differs between the different Halachic authorities so you can find some different figures to those above.