Here you find some manuals that I wrote. They are not typical manuals, but that could be exactly the reason for you to like them (or not). Here's my problem. First, typical books are several hundred pages long, so it takes time to find relevant information. Second, I am a mathematician, so I do not need long explanations and dozens of examples. I am happy with basic definitions and precise rules, I can work out the rest faster than I would find it in books.
Thus when I am learning something new, I read on it, chew on it, process it and distill the material into a few pages. Later, when I need something, I can find it in those few pages easily and I find exactly the information I need and in exactly the way I can understand it best. To my surpise, people were also able to learn from my notes. Before computers came, my notes were handwritten and classmates used to xerox it. But then the 90's came and I could type stuff in, so now I can share it with you - that is, if you are interested. If you like thinking algorithmically, you might like it.
I started with a manual for TeX. I actually started learning AMSTeX first,
so the manual covers both plain and AmSTeX, I hope I separated them
sufficiently to allow the reader to ignore AMSTeX if (s)he has no desire
to use it. I reworked it recently to include some more advanced stuff that
I learned since then, you need not print the last pages (Bonus) if you
want to keep it as a small and handy reference.
You can get it as ps, pdf, or as a source.
Later I needed to learn LaTeX, this time the manual is shorter, since it mostly shows differences compared to (AmS)TeX. Here it comes as pdf, ps, or as a source.
When WWW came, I learned HTML. I am no whiz, so don't expect any Java, but you can do a lot with HTML up to version 4, which is incidentally still the most reliable tool. Once you start messing around with CSS and stuff, you never know what might happen when the page is loaded by some non-standard browser (Explorer comes to mind). Pages coded directly by hand are way cleaner than pages done by some webpage editing software (again, Microsoft comes to mind), consequently they run faster and load much more reliably. If you feel like putting some pages together and do not plan on becoming an expert, this might be the manual for you. Here's all in 16 pages in pdf or ps plus a list of character entities.
Recently I looked into Maple. As usual, I learned a bit more than I really needed and distilled it into 22 pages, here they are in pdf and ps.