Ashley,
This can be done with Tasks or "To Do" work items. To Do work items are Tasks that are not linked to a parent work item (Milestone or Project)... They are a stand-alone Task. If you specify these as Reportable and "Actual Effort Updated from Timesheets) you can have the resources use the Timesheets to update their time on the tasks.
Be sure to specify how the system handles the time based on Submitting and Approval settings for timesheets. See System Settings --> 11. Time Tracking for related settings.
Sincerely,
Boris