Get a good basic grammar like Kelly, and a CD for backup and some pronunciation.
If this work is in preparation for going to seminary in a year or two, then focus on memorization of the basic vocabulary and leave the particulars of grammar till later, unless you just really have time on your hands.
If you can locate someone who already knows Hebrew to some degree, then see if they'll help you with some of the early steps. After that you should be able to move along at your own pace.
Once you have some of the basics under your belt, make it a firm commitment to read your Hebrew Bible every day. That's really the only way to learn to read Hebrew--to dip into it every day. If you don't, it is amazing how quickly all that you learn, whether in class or outside, will slip away and be forgotten.