Tips:
“Turbo Tennis” by Ron
Weite (singles and doubles)
http://www.tennisserver.com/turbo/
“Tennis Anyone” by John
Mills (mostly doubles)
http://www.tennisserver.com/Mills-tip/
Tennis.com
“tips of the week” http://www.tennis.com/yourgame/tipoftheweek/index.aspx
videos http://www.tennis.com/yourgame/instructionvideos/index.aspx
articles http://www.tennis.com/yourgame/instructionarticles/index.aspx
“USPATA(Pro Tennis
Association) Player Development”
http://uspta.com/index.cfm/MenuItemID/1643/MenuGroup/New-USPTA-Education.htm
http://www.thetenniscoach.com.au/tips.html
tennisone.com http://www.tennisone.com/ for super-slow videos
Stretching: http://www.tennisserver.com/turbo/turbo_98_12.html
Strings/Stringing http://www.tennis-warehouse.com/Features/String/StringReference.html