Heat transfer is a very tough subject. When I was doing my MSc a couple of years ago, it seemed fairly straightforward, but it gets a lot harder when you get into it. There are three types: radiation, conduction and convection which is one complexity. Then there are the different shapes to contend with, and the possibility of internal heating. Then convection is dependent on fluid mechanics, which is a difficult subject itself. There is fluid flow over plates and through tubes. Convection may be driven by fluid flow or by buoyancy effects. This is a pretty good book on the subject. It seems to cover all the main topics and their complications. It took me over a year to work through. The maths is pretty hairy. I remember trying to find out what the erf function was and not finding it either in my engineering mathematics book or my Casio scientific calculator. I would like to have posed a few other choice examples, but sadly I can't cut and paste them here. I was somewhat surprised to discover that so many of the mathematical equations were empircal, there appearing to be no theoretical solution to explain the behaviour. There are thirteen chapters with usually over a hundred questions at the end of each chaper. I used to try and do about 1 in 10, avoiding all the questions requiring the IHT computer programme (which I never worked out how to download) and also avoiding all the really long ones and the ones without numeric answers. Even so, the questions were tough, more like assignments than questions. I did manage to work out how to download the answers file from Wiley website, so at least I could see if I got them correct.