Hey Kimberly,
I'm starting a PhD Economics program and cutting down on the number of books and articles that I carry around was a huge motivating factor for me getting the eDGe. I didn't buy it until after the spring semester ended, but I have found it to be very helpful in organizing material for my MA thesis as well as reviewing some math texts that I found online.
In answer to your question, the eDGe comes with a version of "Documents To Go" which allows you to open Word, Excel, Powerpoint, and PDF files on the LCD side (you can also view all PDFs on the eInk). I don't use MS Office Live so I can't say either way whether it will work. Google Docs definitely does (which is similar).
You can actually browse Entourage's ebook store (
http://www.entourageedge.com/e-books.html) and etextbooks (
http://www.entourageedge.com/e-textbooks.html). You can also use Sony's ebookstore. Amazon is releasing a version of the Kindle that will run on Android soon, so you will be able to buy anything on the Kindle store *HOWEVER, UNTIL/IF AMAZON ADDS SUPPORT FOR THE EDGE, PURCHASES MADE ON KINDLE FOR ANDROID WILL ONLY BE ACCESSIBLE ON THE LCD, NOT THE EINK* You can also download books for free from a variety of places like Project Gutenberg.
Honestly, I haven't found any of the texts that I will use in EPUB format and, generally speaking, conversions from PDF to EPUB are pretty disappointing (particularly if the text contains a lot of math). FWIW, I mostly will use it for academic journal articles (i.e., free pdfs) rather than texts.
Right now, there is no official support for 3G from eDGe. But you can connect to 3G via mifi-type devices. For me, I plan on using a combination of a Broadband2go USB modem (pay-as-you-go 3G from Virgin Mobile) with a Cradlepoint PHS300 for when I travel.
Right now, the eDGe has Flash Lite--which isn't all that useful. Full Flash support will come if/when the eDGe upgrades to Android 2.2. Right now, it ships with Android 1.6, but Android 2.x has been announced as something that will happen later this summer (although not clear if it will be 2.1 or 2.2).
If you have an Android phone with a microSD or SD card, then you can purchase apps off the marketplace using that phone and then transfer the programs with the card.