Which one do you intend to get?
Palm PDAs have software that will allow you to sync the data on it, it is relatively simple to use. The Palm LifeDrive can also be connected as a removable drive, so you won't actually need any software to transfer data on that (not sure about the TX). If you keep your files on a SD card, you can just read them using a card reader.
Yes, there are applications for you to open word, excel, powerpoint and text files. Documents-to-go is one of them, maybe you can check if this is included when you buy your PDA? You can also view PDFs and there's plenty of other programs.