While I am an expert in my field upon which I wrote my "How To" book about, I have zero skills as a writer. I released the book on Amazon in December 2011 and between Kindle and Createspace I am making about $ 300-400 a month.
The book is also undergoing a deep revision and professional proof reading. Once done, I will take the next steps to promote it.
The question is as an unknown author and person in my field, is making $ 300-400 a month off my book average for a new indie author? I have no metric to compare this figure to.
Also, I did the KDP select thing for a while and liked it. Is there any other platform out there that is even as close to Amazon to also sell on? Yes, I am looking into BN.
SW accepts word (.doc) files which it then converts via the "meatgrinder" into every conceivable format. They've got this down to a fine art so while your files might not come out of there all shiny and glowing they are more than acceptable. In order to do this and not make a mess their standards are fairly strict, and you'll know if you've failed either through the autovetter (which gives an automatic update) or through a real person checking the file (which is why it takes so long to go premium). If you follow the style guide freely available from SW you'll be fine.
SW itself says that they're not the best platform for selling books. The money from SW comes from the distribution network - there's real money to be made through B&N and iTunes in particular. If you're in the US I'd recommend going with B&N directly, however.
1. If you're US resident, go direct to BN. I did the smashwords route and did very poorly on BN -- when I went direct and could be very specific for my categories, more refined description, etc., I increased my sales about 30x.
2. If you're using your real name, go direct to Apple. If you're not using your real name and want to go direct to Apple, form an LLC and get a tax number for it and use the LLC's name (you'll still be partly discoverable by a more determined person). You'll need an ISBN, but you can buy one from smashwords for $10 (but you have to use smashwords for something to do that, so use them for distributing to Sony, which you can't get through direct yet).
3. Kobo is allowing direct end of June or July, go direct on that.
It's more work to go direct, but you get to tailor each submission to that platform's strengths, which you can't really do on Smashwords. Also, you get your money faster. Time value of money increases the actual value of your royalties.