Deadlock information can be captured in the SQL Server Error Log or by using Profiler / Server Side Trace
If you want to capture this information in the SQL Server Error Log you need to enable one or both of these trace flags.
1204 - this provides information about the nodes involved in the deadlock
1222 - returns deadlock information in an XML format
You can turn on each of these separately or turn them on together.
This table lists the events that can be added to or removed from a trace.