Have you filled out the EPSQ yet? It's an extensive list of questions regarding where you've lived the past 7 years and people who knew you well at each address. They also require information about all your immediate family members and a few people who have known you well for at least 7 years, where you have worked, etc, etc. It asks about drug use, law violations, etc.
On paper the form is about 13 pages. Fortunately the Navy has an electronic version where you can type in the answers, validate that you have all of the required fields, and then email the file to your recruiter.
The reason it's a pain in the ass is because they send a DSS agent to interview some or all of the people listed on the form, review your medical records, and do an extensive police background check. It will probably take longer for crypto/intel/nuke applicants, as they're applying for Top Secret clearance.