What do you do when your husband is unfulfilled in life and looks to you for answers?

I really need some help. My husband has expressed his frustrations to me on many occasions about his work. He lost a very well paying job early this year due to the economy. Since then he has had two other job and has finally found one that would pay him close to what he was earning previously. The problem is that he is constantly frustrated with his situation. He complains he has nothing to show for all his hard work. He is 38 and has worked since he was 18 in the same field. He wants a change and had no direction. It's very hard for me when he looks to me for answers. I want to be supporting but sometimes I just don't know what to tell him. I feel bad because his ex used him to get ahead. She had a child with him and stayed with him while he put her through college and once she graduated she basically dumped him. His dad basically hates his ex because of that. Earlier this year I lost my job and he expressed he wanted me to go back to college so that we could get ahead more. I had a decent job and was able to make some investments and savings, but due to family problems in the past I was never able to finish school and had to work. Now he has given me the opportunity to finish school and I would never use him like his ex did. But at the same time I feel so bad and guilty for him. I will not be far from graduating once I go back to school. Due to many budget cuts in schools there have been some obstacles, but I know I can finish and start a better career. What do I tell my husband? He comes to me all the time in desperation. I have money saved up and he's tried to convince me that we should start a business together with it but I'm afraid of winding up broke. I know nothing about running a business and know better than to try and gamble with what has taken me so long to earn. At the same time I want to support his dreams the way he's helping me with mine. I have a child of my own that is not his though and I think about her future or about what were to happen if he and I don't make it. I need some good advice please. This is the only time I don't know what to say to him. I feel like he's looking for some answers from me that I can’t give him as far as which direction he should take with his life. Now he's been talking to this guy who all of a sudden is his "friend" who works in the same industry as him. He wants to partner up with him and come up with some type of plan. I'm afraid this guy will take advantage of him in some way once he sees how desperate he is to get something going. I feel helpless about all this, help what should I do? I am seeing how vulnerable he really is and how much my opinion matters to me. In some ways that’s scary because he’s looking for strength in me for himself.