Pulp Rack: lots of articles and links to all things pulpy.
ThePulp.Net: a pulp heroes site.
PulpGen. Check out the pulp e-texts. There are even a few stories from Western love pulps. "Team Work" from Golden West Romances is a pretty fair example of this genre.
Adventure House features tons of pulp books and resources. Lots to buy, and free e-texts as well. Check it out!
Back Numbers Can Be Easily Procured, a PEAPS pulp fanzine hosted at efanzines.com -- science fiction fanzines online. (Wow, what a neat site, eh? You might also want to check out trufen.net for fannish discussion.
Harold Lamb I knew through some old paperback bios my dad had of Babur the Tiger, Omar Khayyam, Tamerlane and so forth. Didn't know he wrote fiction. Didn't know he wrote history. But now I own The March of the Barbarians. Mwahaha! You can also read "Rose Face" over at PulpGen.
Max Brand is probably best known today as the author of the novel-turned-film Destry Rides Again. But back in the day, this prolific and powerful writer had stories in nearly every issue of Argosy for years at a time, as well as writing more prestigious novels. Now that I've read a story by him, I have to say his sales were earned. Good stuff, including wonderful description and strong female characters.
G-8 and His Battle Aces site, including a game! (You can get reprints of the series from Adventure House.)
Howard Hopkins has a site featuring his Westerns, his pulp fanzine, and his Doc Savage fanfic novel. Fun stuff!