My office currently went through a process of updating the office standard templates, which consists of 3 major templates for different purposes. Since Revit 2013, you can add more than one template now and have direct access to those templates from the startup page.
|Typical Project Template page|
Here's what you have to do:
The first step is go to Revit "R" icon -> Options
Under Options -> File Locations, you can add more template by clicking the + icon, then browse through your network and find your company templates.
Once you have the template chosen, you can further arrange the order the template:
When all the setup is complete, you will now be able to find all your custom template from the startup page in Revit.