Trigonometry is a strange subject. One way to think about trigonometry is that it is a practical, numeric form of geometry that emphasizes the real world and getting answers instead of worrying about proofs. To balance this practical information, a course in trig will include a long section on "trigonometric identities." The importance of these identities is difficult to discover until you get to some *very* advanced topics in engineering (or somethine else I've missed altogether!)

The most important thing is that you have a really solid understanding of geometry. My favorite tool for learning Euclidean geometry really well is a commercial Windows program called The Geometer's Sketchpad. Add-on modules for the sketchpad include trigonometry, so this might be a great way to learn it.

For calculus, there are many books to choose from. A solid, modern calculus textbook is Thomas' Calculus. Buy it used! This, combined with a Schaums Outline, is an unstopable combination. Thomas is both loved and hated by students and faculty all over, so don't be surprised if there are flames on this one.

If you have trouble finding a book that really suits you, extreme measures are called for. It turns out that there was a 'golden age' for textbooks. Books were written clearly and there was no worry about conforming to the latest educational fads. These years were from about 1958 to 1964. These books were written to win the space race. Many of these books can now be found for cheap at used book stores. The best bookstore for books from this period is Powell's Used Books.

If you have trouble affording the books you need, buy a used book. Also, you may want to buy additional, low cost books to fill in the gaps for your main text. This is especially important if you are teaching yourself, because there will be sections of your textbook that won't make sense. An explanation from another book may be all that you need to make everything clear.

A publisher that specializes in supplementary reading and problems is Schaums. You need Schaum's Outline of Theory and Problems of Differential and Integral Calculus and Schaum's outline of theory and problems of college mathematics: algebra, discrete mathematics, trigonometry, geometry, introduction to caculus.

A publisher that specializes in low-cost books is Dover. I don't recommend a Dover book as a main text. Instead, find a specialized Dover books that cover something that is interesting and uses the advanced math you are learning.

It should work perfectly the first time! - toma