I don't know which ebook reader came with your Axim, i don't remember if mine came with one.
What format is your ebook in? If its in .txt format you need to download an ebook reader like Mobipocket (
www.mobipocket.com). If its in .prc format then you would need to download ereader (
www.ereader.com).
With ereader you can install your book onto the Axim using the ereader pc setup software. With Mobipocket you need to transfer your ebook to your Axim. It will then detect and open up your ebook. I think Mobipocket also reads .prc files.