Hi,
I am looking for the best, quickest way to get used to Salesforce development using a Developer Environment platform. 
I have found two books in developer.salesforce.com:
Force.com Platform Fundamentals
Force.com Workbook
The first one is a 400 pages book and the second is smaller 140 pages.
Can anybody that has reviewed and worked with both tell their opinion about both? Any advise will be helpful.
Feel free to give any other suggestion or advise.
Thanks in advance