Kimberly Killion, historical romance author. She has some really neat information for readers and writers.
Lee McKenzie is another Harlequin American author with an interesting blog.
Romance Writer's Revenge is a site I just purely enjoy for the fun. It also has interesting posts, especially if you're a Pirates of the Caribbean fan.
CataRomance started out devoted solely to category romance (what's now Harlequin and Silhouette) but branched into single title.
Fresh Fiction has so much book stuff, you might get addicted. All genres, and intriguing author blogs.