[url=http://www.roleplaygateway.com/type-turn-based-combat-eden-era-t4212.html]Type 1: Turn Based Combat[/url] is a good read as T1 is by and large the most used and recognized set of rules for textual combat. 

And like that talking melon mentioned, FAQ thread in the Arena section is a good place to ask some basic questions you have and perhaps even set up a practice match to ease you into the Arena.