Simon Palmer has joined this blog as a follower and is asking for advice in collecting Malaya and NB. Welcome. I suggest the following resources:
1.A stamp catalogue such as Stanley Gibbons especially the concise version covering Brunei, Malaysia and Singapore. However, the latest edition came out in 2009 and so the prices may be out of date.
2. Edward Proud's books on postal history. very good for postmarks but are expensive. It is better to get a second hand copy for less than half price sometimes.
3. Join the Sarawak Specialist Society. They have a web site. They cover all areas of British Borneo. The back numbers of their exceptional journal is available on CD. They have published detailed handbooks on North Borneo and Sarawak.You can also buy wonderful stamps at their annual auction.
4. The Malaya Study Group of UK specialise in the Malayan states and Straits Settlements. I have just obtained their CD of the back numbers of their journal for £10.
I hope this is useful to everyone else besides Simon.