Sugar ERD & guidance on doing inserts by hand in SQL to Sugar DB

[joeg]

I'm new to using Sugar and am looking for a complete Entity Relationship diagram to show all the interrelationships/FKs between tables (comments on tables and columns would be nice, too).
I saw the ER for download, but this is restricted to major entities.
I am asking as my client has a web site and they want to register customers for seminars.
I Was hoping to use Sugar to manage this: ie create a call or meeting in Sugar, then use php behind the web page to allow a customer-contact to be added to the call or meeting. I would do the inserts by hand in SQL.

Or, is this not the way to do it in Sugar. Are there APIs for doing inserts thaty I should be using instead.
As I'm a noob to Sugar, I would appreciate any guidance and links you may wish to give me

thanks

[susiewilliams]

Sugar has a Web Services-based API. Go to the Developer website (http://developers.sugarcrm.com) and search for sample code and tutorials there.

[joeg]

Thanks Susie, that looks good to start with.