ok first thing is, it has nothing to do with the domain name provider or anything on that end.
all you ever do at the domain name side is point it to your site.
UNLESS you are using some very funky thing at yahoo where you are merely giving it a full url to redirect people to - in which case you want to go and edit that and what you want to do is change the nameserver of the domain to point to your hosting accounts name server. depending on the control you have their you may need to get them to add the entry for the new domain name.
then in your cpanel for your hosting account you would add cliffnotes.net to your list of PARKED domains (if you want it to be like an alias for your entire site), or else as an Addon domain if you want it to appear like its own complete site but really live in a subdirectory of your existing server [note many hosting providers do not give normal clients the ability to create addon domains].
i'm sure there are other people more expert in this stuff than me who can help out - struggling with this stuff can be extremely confusing when it doesn't work right