As the title says: how did you find this wiki, or how did you start editing? :)
As for myself, according to my edit history it was in November 2008. I don't remember the details, but at the time I was playing Civ4 and somehow found this wiki, virtually abandoned. At the time it was actually a separate Civilization IV wiki, which later got merged into this common Civilization wiki. The common wiki actually had [[User:Robin Patterson]] editing it.
So anyway, I was already a seasoned Wikipedian, and with no other editors present I just started boldly working with everything, creating new templates and articles. It seems that I went quite crazy, carefully copying data manually from Civilopedia and amassing some thousand edits (many page renames included) within the first couple of weeks.