Without a book, you'll suffer. Even when you partly get TEX very cheaply, you will not get around buying a book, that introduces you to TEXṪEX is so powerful as a programming language, knows more commands than any DTP program, grumbles in various ways and now and then produces things that do not make sense. Only a book can help here.
As there is also quite good German literature, I would like to introduce two books that are worth buying.
Einführung in TEX, Norbert Schwarz, Addison Wesley, 1988, ISBN 3-925118-97-7
LaTEX – Eine Einführung, Helmut Kopka, Addison Wesley, 1988, ISBN 3-89319-136-4
If feel your English is adequate (another smiley -TT) there is only one choice: The TEX book by the inventor himself.
The TEXbook, Donald E. Knuth, Addison Wesley, Reading, 1988.
Thank's to Thomas Tavoly for translating the docs! Georg Heßmann, 30. July 1991.