Welcome to the forums,
Device Manager is included with Desktop Manager. You get both with one install. Desktop Manager allows you to sync calendar, address book, memo pad, calendar, etc. and backup your device data. However, usually being on a BES does this for you wirelessly with the Enterprise Server.
Desktop Manager also allows you to load software on to your device.
Keep in mind, however, that all this hinges on whether your company's corporate IT policy will allow it. They can block any of these features as they desire.
The BB is not really a data storage device. There's just not enough memory on the 8700. The Pearl and the, soon to be out, 8800 have microSD slots and can store data.