Hi. First of all, yes it is a whole new world for you, so I really don't know where to start. I think the best thing to do is giving you some advice, than maybe if you have another question mark in your mind about a particular subject, you can open a new topic in this community. To begin with, your device is a HTC Apache coded device, where you can see the detailed specs here: (http://www.pdadb.net/index.php?m=specs&id=332
). After that, here is the link for the forum special for your device, where you can find updates&solutions: (http://forum.xda-developers.com/forumdisplay.php?f=252
). Also, you can start learning the basics of using the Windows Mobile Operating System here: (http://www.microsoft.com/windowsmobile/en-us/help/default.mspx
). And finally, when you move across a little bit, you can start to have a look at some of these great freeware applications for PDA's here: (http://www.1800pocketpc.com/
), which, I think, is the greatest advantage of a windows mobile based PDA. Also, ISP stands for "Internet Service Provider", which in your case is same with your mobile carrier (because you'll connect to internet using your sim card). You can easily contact your mobile carrier (like Vodaphone) and learn their specific configuration for the data connection on your mobile. Hope this helps. By the way, your device also has a built-in wireless, so you can connect to any wifi network around and use the internet through it.