I was recently hired for an IT position that required a Secret clearance. I had read a great deal about obtaining the clearance and had help from my prospective employer that made the process much easier. The best advice (as an earlier poster noted) is to tell the complete truth. Leave nothing out, no matter how embarrassing, because the people doing the background checks and interviews will check out everything. Also, make sure that you check your credit report and be aware of any criminal records that may be hanging around from your past. Secret level checks go back seven to ten years, and top secret will be at least ten. The security officer at your firm should be able to answer any and all questions you have. I was told that interim approval would take 2 to 14 days and full approval could take up to 6 months. With no criminal record or associations with foreign nationals, and a fair credit score my full approval happened within a month. It can seem daunting, but the end result is worth the effort. I hope this helps.