3com 3CRWDR100A - File sharing

I have a 3com 3CRWDR100A modem router connected by ethernet to my main PC and by wireless to a second PC. I would like to be able to access some files and internet favourites on the main PC when using the second PC.
Can someone explain, fairly simply, if this is possible and how to do it!

If you are running Windows XP, go to Network and Internet Connections in Control Panel then select the task 'Set up or change your home or small office network'. Run the Wizard, select 'This computer connects to the Internet through a residential gateway..." then, a little later select 'Turn on file and printer sharing'.

Repeat the process on your other computer (don't use the 'Set up a wireless network..' task on the computer that connects wirelessly but do choose the wireless adaptor if offered alternative means by which the computer connects to the Internet). Make sure you choose the same workgroup name in both cases (default is MSHOME).

You should now find that each computer can view the contents of the Shared Documents folder on the other computer.

Alan, thanks! The other PC uses 98SE. The main thing I want to be able to do is to use the same Opera Bookmarks - don't know where they are stored or how I go about it. Also what basic security should be set up on the router?