Three things to remember and do.
1. think about the design you want for a while before you get it. I have wings on my whole back 50+ hours of work over about 4k. I always wanted wings on my back and it was 6 years before I got started on it. SO find the design and think it over a while to be sure you dont regret it. If your tattoo means something or represents something that is important to you its a plus as well.

2. Research the artists youy are going to have do the work, look around compare each artists, dont get a tat on the spur of the moment if you do your research you will be able to get your tat done by someone that is good at it..

3. remember your future in the job area, if you can cover it up go for it if you cant make sure you are willing to possibly not get a job because of your tats.

Thats about it, just remember to take your time in selecting the atrists and tat. after all it will be with you till you die.