The following show commands can be used to examine OSPF operation and access OSPF statistics:

command	description
show ip protocol	This show timers, filters, metrics, networks, and other parameters
show ip route	This shows the routing table
show ip ospf interface	This will verify you have configured your interfaces into the correct OSPF areas, show timer intervals, and show adjacency levels.
show ip ospf	This will show the number of times that the SPF algorithm has been run and the link-state update interval (assuming no topological changes).
show ip ospf neighbor detail	This shows a detailed list of neighbors, their priorities and their state (ie, ExStart, Full, etc).
show ip ospf database	This shows the OSPF topological database, the router ID and the OSPF process ID. Additional information can be gleaned with more keywords.

You can use the clear command to clear our specific or all routers. The command is as follows:
clear ip route *      Clears all routes in the routing table

clear ip route destination network     Clears a specific route

The following debug commands can be used to view OSPF activity:

command	description
debug ip ospf adj	Displays adjacency events
debug ip ospf events	Displays OSPF events
debug ip ospf flood	Displays OSPF floods
debug ip ospf lsa-generation	Displays ospf link-state advertisement generation
debug ip ospf packet	Displays OSPF packets
debug ip ospf retransmission	Displays OSPF retransmissions
debug ip ospf spf	Displays OSPF spf
debug ip ospf tree	displays ospf database tree

I have added the following Flash presentation in an effort to simplify the understanding of the various states, steps of operation, and use of packets types in Single Area OSPF.