a little help

[knockstock]

im trying to create a website, that will allow members to log in, and be able to add photos on a gallery, add to the forums, have there own profile ... etc

i dont fully understand web design, but am reasonably good at researching and figuring these things out, however, i have no idea where to start with this log in stuff.

my question is can anybody give me a basic idea of what i need to do?

what software or applications etc ..

we have a domain, and databases setup

just a general idea in steps would be great

so i can research and piece it together