Your local library may also have some cover letter and resume books with lots of samples to review.
I'm also including below a link to The Parent's Guide to High School, should you need some info about the academic, social and developmental milestones and potential issues for children in high school.
I am very serious about this piece of writing. Your CV can certainly tell more about personal achievement and experience, but cover latter is also able to give the characteristic of your personality. Of course, if there are lots of mistakes there it is difficult to prove that you are educated and careful person. That’s why I always send all papers for proofreading to professional website. It helps me to feel more confident and it is always great to hear the opinion of the specialist.
I inserted the resource below just because it is truly amazing. In case you need your paper to be written, edited or proofread - this service is for you. I had doubts as for online services like that but after applying for help on here, I realized that not each and every service in the Internet is profit-oriented. There are still some, which are aimed on helping people with their troubles while studying and it is really good to know.
I must appreciate you for coming here and asking for suggestions before going further with your application. Because you may get rejected for many reasons that you never consider as quite serious, but it's true. What I can suggest you considering the level of the placement or job position you are going to apply, you must consult with a resume writing expert (I have used one such service http://resumeplus.us in my need) and I'm sure they can suggest you needed things to be presented in your application. There is nothing going to work better that having heard the words of an expert from the field and I hope you understand and go for a veteran's advise on this matter.
True, a flawless application is the best to attract positive attention. Some people possess certain charisma and outstanding interview skills, but those are pointless unless you manage to land an actual interview. The most reasonable thing to do is to get in touch with a career coach or at least hire someone to polish your resume. A while ago I've read a perfect post that can be useful to any jobseeker. Here it is: