Here is step by step to download ebooks to your iPhone:

Step 1: First you must download Stanza. Stanza is a free app that will allow you to read ebooks on the iPhone or iPod touch. Download Stanza from iTunes

After you’ve downloaded it onto your iPhone/iPodtouch you will need to download another program for your desktop here

Stanza Desktop is a desktop application for reading ebooks and PDF files on your desktop. We will use Stanza desktop “Share” feature to upload our own ebooks onto the iPhone/iPod touch.

Okay now lets get down to business, with Stanza Desktop installed on the desktop and open we can start. I downloaded a random ebook from Project Gutenberg Top 100 to demonstrate. The ebook is Pride and Prejudice by Jane Austen, ebooks are almost always in PDF format, so it doesn’t necessarily have to be an ebook it could be any PDF file you want to download onto the iPhone/touch.

Open the ebook/pdf file by going to “File” and go down to “Open File…” and browse through the directories of your computer for the ebook. Click “Open” to finish.

The Ebook/PDF file should now load into the program.

Now that the ebook has loaded go to “Tools” and make sure “Enable Sharing” is checked.

So now we get our iPhone or iPod touch that’s connected to the same network as your computer. Launch “Stanza” on the iPhone/touch

In the “Library” menu hit “Shared Books” and give it a few seconds to connect to your network. Now your computer name should be on the screen mine says “Books on Master-PC”, click on your computer name and give it another few seconds to scan. Now don’t go to far away from your computer cause Windows is gonna ask if you want to allow a connection between the two devices. After you’ve allowed the connection the book should appear on the iPhone/touch.

Click on the ebook and on the top you will get the option to “Download” the ebook or PDF. And Done !