Fortunately for me I have a pretty solid skill set in a variety of areas. The logo I use (my avatar but bigger) Is my creation. The inspiration from it came from the guy who made my T-Shirts... He was good. I had a different logo initially, and based off of that (a coyote singing into a microphone with a moon as the top) he modified it to what you see to the left.
For a better version check my website:
www.thekaraokekoyote.com
One of the bars I work at had an old bud light light box that didn't work. They were going to throw it out, but I asked for it and recieved. I made a graphic for it using adobe photoshop, and fixed the light box for $10. Home Depot was able to print and laminate my graphic for $18. It looks very cool, and it is hanging on the wall of one of the bars I work at.
The website is mine also, and is hosted for free. If you can use microsoft word, you can design you own karaoke website. All you want is something that you can post your schedule, your contact information, and perhaps pictures from your show.
Get a myspace page. Go to the myspace page of the bar you work at and post friend invites to that bar's friends. Over time your friends list will grow, and you can periodically sent bulletins to those folks.
Collect email addresses like they were gold... they are. I have a jar that specifally asks for email address on it. When I get private gigs, those folks who hired me always get added. Don't abuse it, but send out periodically.
The T-shirts are fun, and give you something to give away. I use "tickets". every time someone sings they get a ticket, and I give away on T shirt a night (maybe two if the rotation is really long). The T-shirt has my logo on it and contact info. Very cool to go to a bar and see someone wearing your logo!
Always loosing pens out of your books? Great! Make sure those pens have your company name and contact info on them! Easy and better than a business card... its something that someone will actually use on a daily basis.
Just google "the American Pen Company"
Business cards are fine, but they aren't a great marketing tool. I only use them when I'm going to bars looking for a job, otherwise I give away a pen.
Bar business cards with drink coupons are great. If your bar owner is any good, he'll have some made up. Ask for them. Give them away at you other venues to good singers who compliment you on your show. Sign the back, and put down, "only valid on X karaoke night....etc."
Look for meet up groups, and karaoke enthusiast web sites. Most will post your shows has a courtesy so singers can find you. If your lucky they will come out to review your show and (hopefully) plug your show in their blog.
www.adventuresinkaraoke.com
I never advertise in the paper or print. Its too expensive and you can get better results when you directly market to the karaoke scene in your area.
Hope this gives you some ideas.