Brush up a little about the company. Don't stress too much; probably not the time to cram up about the field right now. Relax and ace.

 Thank you, Stiffler

 Dress up, a firm handshake, be confident, do just a little research about the company...

if you do not know the answer of any of their questions, just tell them you do not have that idea and you will look into it. 
if you have any recurring actions when you get nervous, work on those.

carry your resume, a nice pen, a piece of paper in a nice folder.

ohh and think of few qualities that you would associate yourself with.

Good Luck!

What's your weakness?
Sh** gets me everytime.

 When they ask you if you have any questions? Do ask them. Read this AMA on reddit, there is a lot to learn from a HR guy's perspective:
http://www.reddit.com/r/IAmA/comments/p23nq/i_am_a_hr_manager_i_want_to_help_you_get_and/

check in google. But be sure to answer questions for strenghts and weakness. and for your weakness, try to give some solution that you are doing, most of the questions that HR ask is behavioral and situational type. Technically these questions are difficult to answer but make sure you would have answer for those as well.. the first questions would probably be like 'tell me about you' or introduce your self.. for this make sure you give your qualifications along with your introductions.. this question simply means why the employer wants to hire you.. please make sure once ur done with ur interview, write a thank you note and send them via email. 
** from my experience, if they really need you they would hire you regardless of your qualifications. But it doesn't apply to all the situation and I am just saying beacuse I am also in healthcare field. 
** Some times HR might talk abt the status as well which they are not supposed to ask during the interview. B prepare for that also
** If this is your first interview, then i m sure u r nervous but make urself comfortable with them, dress appropriately and dont use any perfume or body spray unless your body smells..
** After this interview, you will get used to with and will know how it goes, the general questions that all HR ask, 
** B sure to take ur extra resume, copy of your recommendation letter as well,
** if you dont understand the question, its better to ask them or ask to clarify it rather than answering it w/o getting the questions..
Sorry I had the some of questions that i made for my interview, but i left copy at my home N could not remember all of them.. Hope this would help you.. 

 Thank you guys, I really appreciate your time and advice...
Good nite
HN