Build a graduate course on credits you've already earned. This can drastically decrease the time it takes for you to attain a second degree, especially if that degree is in a field closely related to the degree you already have.
Attend online courses whenever possible. These courses allow you to work while maintaining full-time student status, and can be made to fit your routine easily.
Take your time. Balancing a professional career and full-time classes can be challenging. Consider going part-time, or even on a course-by-course basis.
Prioritize your time. Education is extremely important, but it should not detriment your job performance. This means no all-night cram sessions. Loss of sleep can have significant negative impact on your daily activities.
There are innumerable federal, state and private scholarship and grant opportunities for non-traditional students. Contact your local or regional colleges. Admissions counselors can list most degrees and grants available in your area, and the requirements for them. Also, find out if your employer offers any incentives to further your education.