Easiest way to link laptop and PC ?

I just bought a laptop and I'm interested in transferring files from laptop to PC and vice-versa for my business. I would also like to keep internet access on both machines, currently a dial-up service.
Can anyone give me some school on this subject ?
I haven't linked two machines together since using Laplink under DOS. A quick look in the archives showed me that networking now has a lot more options and seems to be a lot more complex than it was when I linked two machines together and I definately have not kept current with the technology.
What are my options and what are the costs ?

Thanks,
What a great service !!!!!!!
Keith Thomas

 

More info first please.

What operating systems on the two PCs?

Do either or both already have an ethernet network card installed? It looks like a giant phone plug. If so, which one(s)?

You can connect them and share files fairly fast using the parallel port (printer port) or somewhat slower using the serial port.

But the internet piece will need a more modern sort of networking. USB can work but the ideal is with the regular ethernet network cards (what folks are talking about when they just say Network Card or NIC).