Ok. These two sites are likely bookmarked by many a Tekumelphile, but both have been recently re-introduced to me, and both have good value for anyone taking up Tekumel for the first time. First, is a site by Barry Blatt, originally written in line with the GOO Tekumel ruleset from 2005, but includes some very nice information throughout. The second blast from the past, is this wonderful re-hash / reference site of the original EPT rules (1975). This site is a gods-send for any GM attempting to rekindle their use of the original rules. Bookmark them! and have a nice day :)
And if you have not purchased them yet, go over to Drive Thru RPG and buy the original rules. While there, pick up the language books, and other offerings to boot.