First of all, I spoke to my career counselor to get some advice. She mentioned some great websites where they posted internship and student positions.
One at a time, I found a job I want to apply for. I printed up the whole job posting and read it from beginning to end. Then, I read it again with a highlighter, marking everything they were looking for in a candidate. I know it may seem hard, but I always stop after highlighting. If you walk away and do some dishes or go to work, you will think of some great ways to present your resume according to the job posting.
When I come back to it, I spend some time brainstorming. I look at the first requirement of this job and think of things I have done in the past that may relate. For instance, at my current position the job posting said I would be reconciling cash. Well, at that point in my life, I have never reconciled cash, but I have been a cashier and carried my own bank when I was a waitress. Although I might not have done that exact job, I have done things that could help me perform that job better.
The career center at my school has a great book that shows you how to format and word your resume. I have referred back to this book multiple times. I suggest you find something similar. I completed a draft of my resume and cover letter and took that, with a copy of the job posting to my career center. I found someone in business to look over my resume and give me some great advice. Not only did she help me with my wording, she made sure I didn’t make any grammatical & spelling errors (ow, I have heard some horror stories about this). Sometimes, just having a separate set of eyes look at your resume, can help greatly.
Then, and only then, I could apply for the job. Make sure all this is done before the deadline. If there is no deadline, try to complete this in a day to make sure the job is still open. I did all this for my first Student Accounting Assistant position. A few weeks later, I got called in for an interview.
You will need to prepared just as much, if not more for the interview. Look over your resume and think about your past positions. Look up common interview question and brainstorm stories or examples you can bring up. Review some of your class material if it pertains to the position. For example, if you are applying for a personal training position, make sure you know your muscle groups and the corresponding exercises. Look up the company you are about to interview with. What do they do? Are they opening a new location? Are they implementing new technology? Have questions prepared that you want to ask them and most of all, PRACTICE, PRACTICE, PRACTICE! Get someone to help you. My brother called me at 6am from a different State just to get his mind on the right track.
Lastly, relax. If something goes wrong, pick yourself up and try again.