Flight Planning is now available with a range of online services. From the basic route with distances, to complete services that file a flight plan with the FAA plus tracking the flights. Here we will provide some examples of some simple options and provide some resources for more advanced flight planning.
SkyVector.com provides a basic planning tool where you put in the airport checkpoints, and it provides a route with the distances and directions. This is great for basic planning but DOES NOT account for winds. Therefore, it can not be used for actual navigation. However, it does provide a great basis to start from.
You can use the distances and directions and add in the winds with wind correction angles resulting in actual ground speeds accounting for the winds. A nice feature is the weather at the airports with the colored bubbles shown.