Hola Edvard,
Welcome to SCN, first of all I would suggest to post your queries in English, most of the people here speaks english so will be easier for you to get an answer in that way.
The second thing I would suggest is search before posting, your topic/situation is pretty popular so I'm sure you will be able to fin what you need just with a little patience and some specific keywords.
Anyway I would recommend this book for starters, i didn't read it, but I own some books from SAP Press and usually are pretty good:
Discover SAP CRM (2nd Edition) - SAPinsider Store
Discover SAP CRM. of Srini Katta - by SAP PRESS
Cheers!
Luis