The following links will drop you into a frame-based wrapper which gives a list of properties down one side, and the actual specification on the other. For the CSS2 specification, the properties are available in a number of "views." You can switch between these views using the "tabs" at the top of the index frame on the left. Selecting a link from the index frame will jump you to the relevant portion of the specification on the right.
The layout used for the following links is based on an idea I saw over at zvon.org, although the execution does differ a bit. Remember: the following pages do use frames! Apologies to anyone with a frames-incapable browser.
Hate frames? If you have a Mozilla-based browser or Opera 6+, you can add similar resources to your Sidebar in either browser. Head on over to either Rijk's Panelizer page or TjL's Sidebars/Panels page (both of which list many more panels than the few I've created).