I have a laptop running Vista and a desktop running XP. How do I compose a document (file) on one and "share" it with the other? They are on the same wireless network. Thanks

Here's the short answer.

You have to "share" a folder or the entire hard drive of at least one of the computers (you can share both hard drives or a folder on each hard drive). You also have to make sure that Windows Firewall or some other firewall (ZoneAlarm, for example) are set up to allow a connection to occur. You then connect from one PC to the shared folder of the other. After that, you can simply copy files as if they were on your own PC.

There are some complications. Usually the two computers have to be using the same workgroup or domain (most home computers aren't on domains) in order to easily connect. I've not used Windows Vista, but I suspect that there may be some complications with that. It should be roughly the same steps, however.