Generate a following in your hometown first. If you don't already have a following in your hometown or a nearby city, it is unlikely that you will have a following outside of your area. Touring is great, but if nobody is there, it is just a waste of time. Play some local shows first to generate buzz about your band.
Make friends with bands from out of town. In many cases if you have played shows in your hometown you will have most likely played a couple of gigs with bands touring from out of town. By making friends you will have contacts for shows out of town who will help get people to come to your show and set it up.
Plan two to three dates for your first tour. Being on the road for long periods of time is often taxing and can cause the band to lose morale if the tour is not going well. To avoid this, plan your first tour for only two or three dates and keep the shows within the next few major cities to your hometown. Contact the bands from out of town that you have played with and book your shows.
Promote your tour. If you have a demo you can send that out to college radio stations and ask them to play it. You can also send a press release to the local paper and flyers to the venue. Use online promotional tools such as Myspace and Facebook as well. Promoting your out-of-town shows a few weeks in advance should get people to your show.