as was already said, remember they are permanent, even though there are removal services now, they don't always work (some inks cannot be removed) and they hurt about 10 times more than getting it done (and you have to have th treatment multiple times) and they leave scar tissue where the tat was.  There are some tips though, one is to figure out what you want and hang a picture of it somewhere you'll see it all the time, if you get bored with the image after a while, do not get it.  Furthermore, do not do it yourself, I've seen so many india ink tats turn out horible and they can be a bitch to cover (also many people are rather succeptable to reactions from india ink).
I would also highly recomend getting something unique and something with meaning to you.  Since it is permanent, there should be some absolute meaning to you, not just a fly by night though or a random picture off the wall (the only flash tat I have is one where I went in, described what I wanted, and the flash just happened to matched it almost identically, a little bit of tweaking and it was dead on).
One trick, if money is an issue and you are an artist, talk to the shop and show them some of your drawings and see if you can trade some drawings for work (I know a few people that have done that).  Remember, with tatoo's, you really do get what you pay for (typically), and there are more hacks out there than there are quality artists.  Expect to pay around $100 an hour for quality work (hell I know a couple people who get in the range of $300-500 an hour).
life is too short to have any regrets