Take your time and learn and all will go well. Basement finishing is expensive but must be done right or it will not last. You can do it all yourself and save 50% or the typical costs. I get about $40-60 K to finish a basement. The bath will be another 15K... so you can save quite a bit of money if you have the time. You have a basement that offers some unique challenges in the fact that you need to deal with a below grade and above grade concrete wall. Insulation is treated differently for the two plains. Read up on articles at www.buildingscience.com to get an idea of what you need to be concerned about. Post any questions on what you do not understand. Do not cut corners on insulation and moisture control or you will be tearing it all out next year. Good luck.