I have the stick on vent visors. They work great in the rain also in the summer. You can crack the window a little while your at work or whatever, and it keeps the heat down without anyone trying to break in.
I have the Haynes manuel. Just get which ever one floats your boat! [img]images/graemlins/chairfall.gif[/img]
Dad bought the Weathertec ones for his 2002 1500. He likes them. Really easy to install. Just pop in one side, and then sort of bend it into the channel on the other side, then roll the window up until it seats in the channel!
They don't stop the rain from coming in, but they certainly do help.
They're about $40-something, but are good quality.