I think it really depends on the field you're going into and how much you really enjoy the type of work you're doing.
I'm not really going into grad school because I think it'll make it easier to get a job, I know it'll probably make it harder for me because there's actually a higher tendency to become overspecialized in my field (Materials Science & Engineering). I'm mostly doing it because after my undergraduate work I realized how little I understand about the field and I really want to learn as much as I can about materials (which is also why I want to have a really heavy research position and also why I pretty much need a Ph.D. in order to get any job I want, but that's beside the point).
You should only go to grad school if you really feel strongly towards the subject or you know you need to do it in order to get a certain job in life.
As for deciding on where to look for grad school you can try looking at the rankings on US News (they do separate for undergrad and grad rankings), talk to professors (a best bet), checking out webpages of various schools, reading peer-reviewed journals on the subject you're interested in and see where a lot of papers are coming from, or when you're reading papers see if there's any authors that have interests very similar to your own. Then find out where they teach or even try e-mailing them to see if they can recommend someone to talk to (if they're not faculty somewhere). You could also look at where people in your department have gone to grad school before you; your school's career center should keep some sort of listing for that. If they don't, again, try asking professors where people with your interests have gone.
Since you're in the liberal arts you'll also have to be more concerned about funding than someone in engineering or science where their graduate education is paid for. If you wind up not being able to afford grad school (or figure it won't be worth the money) then it might not be worth your time even looking into it.
Edit: Also everything Stop Sign said above me in the post he wrote while I was writing mine.
Getting research experience now is probably one of the most useful things you can do to determine if the life of a grad student is one you'll be able to tolerate.
How ya doing, buddy?