Plenty of examples on the net, or even in the UO code. Just get a good global search tool and look for "struct" across the code base. With UO handy, some basic C# docs on the net, as well as the SDK docs here...
http://msdn2.microsoft.com/en-us/library/ms229335.aspx
... I was able to learn C# with little assistance.
To answer your question:
http://www.c-sharpcorner.com/Language/StructuresInCSRVS.asp
http://www.c-sharpcorner.com/Code/2002/July/WorkingWithArrays.asp
C//
p.s. It's bad practice to use structs (use objects if you don't know why you're using a struct) without a good reason; a discussion of when to use them is here:
http://www.codeproject.com/csharp/structs_in_csharp.asp