I work at a small Web Dev firm, and have been handling all the PHP/MySQL/etc. for a while. I'm looking at improving our practices to allow for easier collaboration as we grow. Some things I have in mind are:

• Implementing a versioning system (source control)
• Coding standards for the team (unless mandated by a certain framework, etc.)
• Enforcing a common directory structure for our Desktops (for backup purposes, etc.)
• Web-based task/project/time/file/password/contact management and collaboration app(we've tried a bunch; I may just create one)

What do more experienced developers view as necessary first steps in this area? Do you recommend any books? One thing to consider is that the bulk of our daily tasks involve maintenance and adding minor functionality rather than new projects, and the team size will be between 3 and 5.

I just found a related question about teams that will be expanding from a solo developer.