Hi,
Personally i am an eReader fan and all was going well until they locked down the countries.
I did try going the Stanza approach that NZ_Ark uses but the "magic" was all a bit much for me.
I found a programme called BlueFire Reader and I use the Whittcoulls or Books on Board or … websites to purchase ePub books, then instead of downloading the books I copy the shortcut to the link and email it to the iPhone I want the ebook on (mine or Hubbies) that way he only sees the ones he might want to read.
In the email app click on the link and it starts to take you to the web, and then comes up asking what programme you want to open in BlueFire or …. (depending on what is on the iPhone), select BlueFire and it begins downloading.
Since Whittcoulls is powered by Kobo I imagine you will be able to copy the download link in a similar way from their site (not one I have tried).
Once it is in BlueFire it is available to save to your computer via the link under iTunes, I like to save the files as a backup, just in case. Once you have the file saved on your computer I guess you could import it into iBooks, but I haven't tried, BlueFire does the job well enough.
And of course the library via Overdrive is great, but I sometimes the time limit is a bit of a pain depending what you are doing at the time besides reading :)
Happy reading