Please bear with me as I give some background on my organization so I can set the stage for the issue I am having.

My organization is completely run from a website. It is somewhat of a subscription-based search service where parents and babysitters can locate each other. I will have thousands of users that will come to my website, fill out a seperate registration form AND questionnaire form/profile (will be rather lengthy) pay for level of service they want, and then perform searches and other functions from their homepage/dashboard. (similar to what you see on www.enannysource.com)

I will have 2 types of users: parents and babysitters (I assume I should create 1 application for each?). Each will need the ability to login only to their account, and to edit/delete their own records but also be able to search the other database (ex. parents will need the capability to search the babysitter database and vice versa). 

Because I will have thousands of users creating their own accounts on my website, I want their experience with Zoho to be seamless. ie - I dont want people to have to create an account with zoho before creating an account with my website -that is simply too cumbersome and illogical. Any suggestions on how I should go about this? The only thing I can seem to find is information about making each visitor to my site that fills out a profile a zoho user and if thats the case, this will be a huge letdown!