Just throw some online (nmap) scan against your box, try to xploit your local RPC services or try to login to a remote POP3 server using my plaintext "login" rule:
alert TCP $HOME_NET any -> $EXTERNAL_NET any (msg: "LOG Plaintext LOGIN snd"; content: "|6f 67 69 6e|";)
You can't compare Snort to LIDS. If you do, at least put some effort into making a case why you would do so.
Installing through RPM makes things easier for some people, at some times of day under some weather conditions, when the planets near a good conjunction. YMMVVM. Especially since you stated using Slackware.
Maybe do a bit RTM on IDSes :-]