NCSU College of Physical and Mathematical Sciences: Department of Mathematics

Take both the general portion of the GRE's (Graduate Record Exam) and the subject exam in that area. Usually students take the general portion in early summer before their last year in school and the subject exam in November of their last year. This schedule allows the student to retake any part of the exam if the score is not satisfactory. In addition, the student will have taken the exams early enough to meet most of the deadlines for applications for assistantships and fellowships.
Check out the schools you might be interested in. In particular, check out the ranking of the various math graduate programs. All of the honors advisors have copies of the latest ranking of US math graduate programs as well as some information about job possibilities after the Ph.D.
Check out possible assistantships and fellowships. The American Math Society each year publishes Assistantships and Graduate Fellowships in the Mathematical Sciences which contains (as you might suspect) information on assistantships and fellowships in mathematics at various schools in the US and Canada as well as national fellowships. Dr. Paur has a copy which you may borrow and your advisor may also have one.
Check out national fellowships:

   NSF
   DOD
   NPSC (for women and minorities)
   others

You can get more information about these fellowships and others from the Fellowship Advising Office and the Graduate School. You may also want to visit the Oak Ridge Ridge Institute for Science and Education web site.