I need to set up users to dial into their computers using notebooks and cell phones,they should be able to dial into thier individual machines and then have access to thier files on the server.I'm thinking of using pcanywhere but I've never done this before.
Well this is not really a difficult thing to do, the issue might be that they would have to dial one number regardless of where they are.. and that number wouldn't be local..
you could consider VPNs.. (virtual private networks) which is basically you set up VPN software on the laptop and a VPN endpoint in your company.. the user just connects to the net wherever they are and the VPN securely tunnels your traffic over the Internet..
the advantage is you make use of the ubiquitousness of the Internet and its already existing infrastructure. Once they're connected, it will appear to them as if they are on the local LAN and can access whatever you want them to.
Products like PCAnywhere are also worth a shot. You could try GotomyPC, a lot of people seem to like it and all it requires is a net connection and a web browser.. I believe Tom has some experience with it so he'll probably give you more details.