Grid is a complicated addon that folks use for healing and other things. WOW Insider has compiled a list of links to help you get it up and running.
http://www.wow.com/2009/10/19/the-daily-quest-grid-healing-addon-guides-and-resources/
If you want something simplier that is built to heal and buff/debuff, search the blog entries using "Healbot."
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The Solo MMO Player collects links to the most useful or interesting MMO websites, databases and blog entries I have found, with a bias toward topics of interest to the Solo Player. Use the search box in the upper left hand corner to find topics. Kelari NPC Warrior art courtesy of Game Fluid.