Search the link you want, give it as the web site address, give the "scan
depth" the depth level of pages you want. If you want only 1 level of pages
below this link give scan depth of 1...or 2. Try with 1 first.

As to your other question, all you need is to learn how the scan rules work.
The help html pages and other text files in your installation directory should
be sufficient. In theory just permit the links you want as

-* 
deny everything first
+http://www.server.com/dothisorthat.asp*
permits only links/pages which fit that. If you do not understand what that
means you need to learn what a wildcard (*) is.

Applying the correct scan rules is not always easy, you need to study the
names of the links and what they point to. Use the "view source" command in
your browser and think what the current link address means. 

Sometimes certain files are stored even in other servers, to find this out you
have to see the properties of both the page which contain the link to
somewhere, and the page that is produced by clicking the link.

You have to think a little, it will not happen just by clicking a button, the
program cannot read your thoughts.