Looking to build a website that integrates actual bitcoin transactions.  What sort of documentation is there for the API for making transactions through php?

Also, say I wanted to dump all previously created bitcoin transactions into a MySQL database.  What would be the best way to do this and keep said database regularly updated with the latest transactions?

I could datamine from blockexplorer.com with some sort of a crawler, but I figure there's probably a better way to go about it. 

Thank you much!