I'm using Microsoft's SQL database software. I'm quite new with databases, so I'm wondering if anyone knows of a great tutorial? I'm creating a website that will need user accounts for login where users can upload a document and where others can view that document with a security code. Like "Enter the four digit security code to continue". For privacy, of course. This is the main goal for the database.
Try http://en.tekstenuitleg.net/articles/software/database-design-tutorial/intro.html (Be prepared to spend at least a few weeks studying the subject - it's not trivial.)
Use can use w3school for SQL . For SQL server go to Microsoft website they have great tutorial for each topic of sql server.