The organization of OSPF material has the following drawbacks: a) lack of context, the commands are covered only after some theory is given in a dry definition form. This is great, you may say, but to me it was not easy to put the definitions into context. The material for OSPF is mostly from the Cisco OSPF Design Guide (read those skimpy pages to get the most understanding of OSPF). So it looks like from the OSPF design guide, they seperated the theory and interspersed it with some other text and moved the configuration towards the chapter end. The second OSPF chapter requires serious apology to the readers: inter area routing and external routing are impossible to describe and make students understand without introducing redistribution(this is introduced only at the end). However, this makes the material extremely difficult to understand.
EIGRP is OK.
BGP is another complex set of definitions, and several reads are needed before even trying to piece together the definition and understand how to put everything together.
So: for OSPF start from OSPF design guide by Cisco. Not sure about where to go for EIGRP and BGP: I got a hang of those material by several reads of the Paquet and Teare material.