Novie networker in need of some advice.

Ok so here is a little background, I am a long time windows user, have never really had any problems with it but I am really liking the essence of the whole mac world. I am not completely ignorant to most computing things, give me enough time and I can figure most out. What i want to do is switch completely to a mac based home network. I am no networking expert and common sense doesnt even work with me here, So If you give any advice please be clear. I do apologise for my retardedness. ok back to the point. My Mac home network. So there are just two people in my house hold. What I would like to do is get one macbook or macbook pro, and one imac for each person. So now were up to four computers total. Now I want to sync one laptop to one imac and the other laptop to the other imac. Both with password protected accounts. Now here is where my network inexperience comes in.. If I have created a network between one laptop and one imac will all files that I have like music files and word documents be automatically synced between the two computers. I would like them automatically and instantly synced. I dont know if I need a server for this or what... Also I am going to be a road warrior. Travel will be my thing. I am actually looking at wireless WAN routers for my car that pick up cell phone signals and broadcast a wireless signal from my carl. I would like my laptop to automatically sync up to the Imac anytime it connects to the internet. The final thing I would like would be to have wireless back up for my files. I have heard the Time machine has some (or a lot of ) problems with user interface. Can anyone give some opinion like using a external hard drive and time machine to do backups. thanks to anyone who posts a response. If anyone would like to give me some networking advice that would be great.