Borrowing computer access, so only a few links. The best sources you could ever want for canon support for Kirk/Spock can be found neatly wrapped up in Killa's superlative essay "Where No One Had Slashed Before" found at Ship Manifesto. It's also a sterling example of fannish love.
http://www.livejournal.com/community/ship_manifesto/39288.html

And once you succumb to the power of K/S, Killa also maintains a site containing some of the best recpages and linkpages around. Her primary rec focus is on ST-TOS and Highlander, but she also has a large section of other fandom recs. Killa has fantastic linkpages for ST-TOS, Highlander, Starsky & Hutch, and Jeremiah, and a misc fandom linkpage.
http://seacouver.slashcity.net/killa/linkpage.html