In BO two path is there, first decide what option you are going to choose
1.Administration
2.Development
first understand the basic things using the Offical Learning Product tutorials from the below given link
then goto Product help documentation to get more knowledge.
Official Product Tutorials - SAP BI Suit
For Administration
- SAP BusinessObjects BI launch pad
- SAP BusinessObjects Business Intelligence platform
Development
- SAP BusinessObjects Web Intelligence