You have specified your Tests and organized them using Test Sets or using the Test Repository and now you want how to address properly the planning phase of your testing, right?

In fact, you may start by creating a Test Plan and then create the Tests and add those to the Test Plan.

Planning your testing is also dependant on the methodology and process you're adopting.

Some usage examples 

Planning, from an "aiming" perspective

Planning, from a "methodology" perspective

Agile

Scrum

Waterfall

In this scenario

Iterative Waterfall

In this approach, a release is somehow split in some internal mini-releases with subsets of the features implemented and it may be assumed that some of these features may not be complete/stable/finished.