You write an ebook and download it, preferably as an Adobe PDF file or some other format that suits you, onto your web hosted storage space. (This is usually done using an FTP (File Transfer Protocol) program like CoffeeCup Software's FTP program (you can get a free copy)
You can password protect your PDF files or use some other method, but it's a pain in the butt for buyers and in the long run is probably not worth the trouble ... risk manage your security. There are some things you should do eg, make your directory with your saleable files invisible to the search engine robots, but don't worry about that for now or you'll get even more confused
Hosting companies can help with a range of things, but often want additional fees (which is reasonable)
You can hire people to write books from such places as www.elance.com and others. If you pay them to write for you, the Copyright will be yours. But make that clear in any memo of understanding or contract you write.
Private Label Rights are also available. Do a search for something you like eg, "women's health private label rights" and see what comes up. Some of these are expensive and of course you need to make sure that rights aren't given to thousands of people.
Clickbank at
http://www.clickbank.com can set up an account for you to handle your sales, affiliate programs etc at very minimal cost as can Paypal (See
http://www.paypal-australia.com)
Good luck. You are entering an interesting and potentially lucrative business.
Regards
Robin
http://www.dwave.com.au
http://www.employment-one.com/blog