A good beginner's cue is what ever feels right for you.
Efren Reyes used to play with a $10 - $12 house cue and was really good with it.
I recommend Cuetec, Viking, Predator, or Lucasi. McDermott is not bad either.
J. Pechauer makes really fantastic, well-seasoned cues.
Try to find cues threaded with a 5/16-18 or a 5/16-14 joint pin, you will be able to find and try a wide variety of shafts.
Don't really go for the intricate inlays and flashy patterns on a cue because it really does nothing to up your game other than provide a shot of confidence. Also, the more inlays you have, the more you loose the feel of the cue as the feedback will be translated through these inlays and not so much the wood. We want to be able to feel the wood.
If you are serious about taking the game to a professional level and have set your heart for this, then dig up a few hundred dollars and invest in a serious cue.
It's not a waste of money to buy a 1,000 dollar cue if you plan on using it FOR LIFE - but keep in mind - even a 300 dollar cue plays well. Remember the 12 dollar Reyes cue. Make sure your budget is well suited for it as well, really important.
I play a 300 dollar Lucasi L-D2 which has served my purpose well - observe the simplicity of design.
A medium hardness tip is perfect for the beginner. It's low maintenance with good control. The best brand out there is Moori at the moment - Kamui tips are pretty good. I hear many people preferring LePro or Sniper tips - I prefer Moori and Kamui. Try one of those out or try a LePro.
Also, when buying, check the weight. 19oz comes standard in cues. Heavier cues in the 20-12oz range can impart heavy spin on the ball and shot errors are masked. The lighter the cue, the easier it is to do something wrong - you need to finely tune your shot stroke with light cues, I feel that's the way to learn though. Then again, I started in snooker with 16oz-15oz snooker cues, I love lightness. 19oz is in between, just nice.
Go to your local billiards store - try out different cues within your budget. Ask about the joint pin, the construction, the tip and the weight. Ask! Ask! Ask!
It's just like buying a car - you need to make sure you just spent that money on something worthwhile and tailored for you. Worst comes to worst, you bought a crappy cue that doesn't feel right for you and it frustrates you.