I don't read all that much Steampunk, (at least, not compared to some other genres) and a lot of what I have read I forgot to note down the authors so I could find them again later, but you can't talk about steampunk without mentioning Girl Genius, by Phil and Kaja Foglio. There's the webcomic, of course, and the graphic novel collections thereof, but they've also got novel versions of the first three overarching storylines. I've only read the first two, as I haven't had a lot of cash recently to buy books (which would be why I haven't bought the latest collection of Instants yet, 'Nutter, your traditional $20AUD is coming), but they're both highly enjoyable.
Another author I would recommend would be Jim Butcher. He's got an in-progress Urban Fantasy series (the first book of which was done when he was told to write the most trite, formulaic thing he could, but make it good), a completed High Fantasy one (that the first book of was created on a bet that he couldn't take two ideas that in no way fit together, and write a good story out of it), and a just-started Steampunk one (I don't know the story behind this one, but I wouldn't be surprised if someone bet or challenged him - seems to be a pattern). I think only the first novel is out, 'The Aeronaut's Windlass', but I've been avoiding looking at what's come out recently, so as not to taunt myself with things I can't afford.
The only other Steampunk author I can recall offhand is George Mann. I've read a few of his novels in the Newbury & Hobbes series - the ones subtitled with the gloriously verbose "A Newbury & Hobbes- or A Maurice Newbury investigation". They're essentially Sherlock Holmes pastiches, but very enjoyable ones.
Maybe have a look here? Seem to be a few authors of the female persuasion listed.
If you can find it, there's a few graphic novels of Atomic Robo that deal with Robo's creator, Nikola Tesla, and the adventures he got up to with a group of like-minded adventurers, and they're steampunk, quite distilled steampunk at that, considering the rest of the series is set at various times in the 20th and early 21st series, so they really condense it down. I think they're under the Real Science Adventures label, or something like that? Don't have my copies with me, to check.
