As a CPA there may be busy times of the year when you need extra help from those in remote locations. For this and many other reasons having a collaborative task manager is essential.
Although there is a previous post on using Basecamp for project management, the free option is somewhat limited. Used in conjunction with the Workteam Collaboration Suite, Zoho is a useful way to manage projects alone or collaboratively online.

Free Project Management for CPA's
Create the set-up. The set-up process is easy enough and only takes about 30 seconds to complete. Just go here and put in some basic information to get started.
Free edition. Although the free edition does limit you to one project you can have unlimited number of users, milestones, task lists, and tasks. You also get a calendar, reports, forums, wiki, and chat feature. I am going to show you what you can do for document sharing and time tracking two things you don’t with the free edition.
Milestones and tasks. Central to everything is the ability to add task lists to milestones. You can create as many milestones as you want. A task list allows you to create a check list for each item that needs to be completed for the milestone to be considered done.
Multiple users. What is nice is that you can have separate task lists under the same milestone. You can then attach the milestone or task list to other users. This gives a central person control over a project, who does what and where they are at in the process.
Dashboard. You can post updates on what you are working on and keep an updated record of others in your CPA firm. This allows you to easily coordinate priorities and make sure that a particular task is completed on time.
Document sharing. If you have a website hosted by CPA Site Solutions then you could have the Workteam Collaboration Suite. This type of email solution offers online document sharing. This means you can share documents with others online and even have access to different versions allowing for an easy way to collaborate.
Time tracking. You can still have time tracking. Check out this previous time tracking post on how to get that aspect up and running.
Although there are many different options for project management, Zoho is free and seems to offer quite a lot of flexibility for any CPA. When you use it for your accounting firm along with the Workteam Collaboration Suite, you can collaborate effectively with others online.