Welcome, Teresa!!
You will find great info about Axims and more here.
You can use software other than Dell software for GPS stuff, but you will have to buy it! Check out this discussion in the GPS Talk Forum for more info:
Pros and Cons of Major PPC GPS Systems from Users
When you wander around in the GPS Talk forum, you will find a lot of opinions about GPS hardware, software, and how to get it all to work on your PDA.
In addition to the GPS software, you will need a GPS receiver.
I was the happy winner of a GPS contest here on Aximsite/Mobility Site, and won the Visiontac bluetooth GPS, and the Odyssey Mobile Navigation bundle.
You can find out more about this combo at visiontac.com. The last time I checked, they were selling their bundle for just over $100. I am delighted with how the software and hardware work.
Good luck!