There are many things that are very important to know about starting senior year including how to apply and follow through with financial aid, what college you are planning on attending, scholarships (high schools always have scholarships that anybody can apply for! Even if you don't get perfect grades!! High schools offer a variety of scholarships ranging from full scholarships to partial scholarships!! Don't wait and apply for them early, jump on any or all that are available and every bit for money helps out a lot in the end.), college applications (and when they must be due by), and it is also VERY important that you apply for your colleges early!!! Don't wait and procrastinate!! That is probably one of the most important things to know!!
Good Luck your Senior year!! :)
