Re: Shared folders!
are you running XP? if so, simply right click on the drive you wish to share, then go to sharing and security - there will be a tick box there alowing you to share the drive and there is a box below so you can name it to identify it on the network. As for password protection i'm not aware of such a feature within windows, so you may need to consider a 3rd party application which will need to be present on any machines with shared drives.
as for setting up WEP, you'll need to do the one thing that every man hates to do - look in the manual. the reason being that the confirguration process will vary between different routers.
hope this helps