Refer this:-
http://creativeindividual.co.uk/2011/02/create-a-pop-up-div-in-jquery/
http://www.codeasp.net/blogs/raghav_khunger/microsoft-net/1005/jquery-how-to-make-a-simple-tool-tip-plugin
http://plugins.learningjquery.com/cluetip/demo/#
http://www.forclimadapt.eu/sites/all/themes/climadapt/bubblejs/examples.html