In all honesty, there is no better tool than Google. Get a gmail.com account, and make it happen. You will want to access to their calendar app. Wherever you might want to post an event, on a site and you need to register, Google has a tab 90% of the time from which to sign-in (which sometimes I've seen a date I put on Google Calendar do a lot of the promo on it's own. Google is NOT A PUNK out here.
But you have to utilize the sites, be a member, and indiebooker costs. They say they have the best network, but we are the ONE music genre that is on the edge, so you might not find that to be of much value.
One thing I used to do, I would look for a coupon code, discount, or free trial. Compile the list of venues, and then cancel the membership. You only need the venues, everything else they do for artists, probably doesn't apply to rappers, anyway.
Some bar sites have links on their websites that go to pages and have rows upon rows of information on promotional tools like all the college radio stations, commercial radio stations, the newspaper, if they have an artistic community; you can bet they will have a number or email of someone you can get that radio spot while you're in town.
I even look at cable providers, if you know how to cut a short promo of video and get some audio over the clip, the event just reached 10,000 people before you have even stepped into town.
For the price, it's not bad to have that kind of promotion.
Do you see why I've said to plan 4-6 months in advance?
On reverbnation.com there are ways to sell your music online. You can also design your t-shirts buy them at cost and recoup the funds during the tour.
Find download card distributors for your online songs.
Kunaki.com is competitively priced for CD duplication, and you will appreciate the company's flexibility. You have to install their CD making wizard, but it's virus free and you don't even have to have it mixed to wave like bandcamp.com.
I'm not telling you not to get it mastered. If you care, it should show.
But you can upload the album from like a zip. file. It comes in handy when you can only afford 20-25 CD's. Or even one, it's crazy.
You have to be on your merchandising square.
Maybe I lied, because if you have no money to fund this tour (if you're just a hip hop artist and not balling) you need to start looking for ways to make money in your spare time.
If you write lyrics, there's a chance that you could make money writing articles online, or taking paid surveys. We can cover some funding in another post.
You need about $500 to $750... If you got that, then you are ready to launch the process. YOU ARE READYING THE PROCESS AT THIS POINT
For the rest of us, some of these work from home side jobs could expedite the fundraising part.