Tony, as the saying goes... if you have faith the size of a mustard seed you can move mountains... or Great men dream, then put action behind the dream. It helps too that you are passionate about what you are doing, as well as willing to put the $$$ when it is needed.
I would suggest:
1) get Sandra's consent. Without this nothing gets off the ground;
2) get Sandra's input/involvement. In doing so, she also has ownership and shares in your dream;
3) get "models" who want to have their own portfolio of pictures made. Offer a discount -- you are both learning the trade. Start off by advertising in th elocal papers/Herald, as well as referrals from friends, family, colleagues;
4) get model release forms -- it will save you the headache in the future.
5) remember, baby steps... baby steps... take it one step at a time. If you focus on the numerous aspects of the venture it can and will be overwhelming.
6) try to get free advertising -- if there is such a thing... Goodwill on your part will spur this on.
Can't think of anything else at the moment. Probably a cuppa would be good to bounce ideas off...