We started using jQuery about a year ago, with little knowledge and much bitter relationship with javascript. jQuery made javascript more loveable, The selectors is one of the most interesting bit in jQuery, as well as there are tones of freely and useful available plugins on the internet. For a while we got stuck with Microsoft offering , ASP.Net ajax, but it sucks , I got all the UpdatePanel replaced with ajax call and PageMethod cool. If you guys are on Visual Studio check this out, intellisense for Visual Studio.
1.2.6:
http://code.jquery.com/jquery-1.2.6-vsdoc.js
Latest release (currently just a copy of 1.2.6):
http://code.jquery.com/jquery-latest-vsdoc.js