Long time ago I bought a second hand copy of the book Creative Illustration by Andrew Loomis. A spanish version that I could lay my hands on in the Reina Sofia Museum in Madrid. I knew the book from a friend. Long time this book has been my bible, still I look through it once and a while. Excellent explanations on how to draw, how to make a good compositions etc etc. Now this book and some more titles are available in PDF. For free!

Thanks for the tip! Love your work, by the way.
Dear Ben,
You’re probably not aware, but a few of the Loomis books have been reissued.
http://www.amazon.com/Andrew-Loomis/e/B004L5LII8/ref=sr_tc_2_0?qid=1352799895&sr=8-2-ent
Hi Adriano. Yes I knew that. Thank you.
I am learning, enjoy every moment