Adam I recently got into DA, I suppose it depends how deep you want to get into it. For me I found there are a shed load of related topics on this very forum that are full of useful information and as far as painting ideas are concerned Foundry have a picture of every figure they produce on their site which give a very good indication of what your figures should look like.
If you want to go deeper then Foundry have two books on the subject, the East Africa book is difficult to get hold of but I believe the Central Africa book is still available and can be picked up for less than twenty quid.
Jeff