I always check windyty as it has a graphical display of the forecast winds at various levels up to 10,000 ft and above, and also a cloud overlay forecast. It covers 4 or 5 days ahead. You can zoom in and out, and click at any point to get a detailed forecast for that exact location. I used it yesterday and managed to find a slot of a few hours when winds were light and cloud at around 30% to plan a flight to the 12 Apostles, a destination that has eluded me a couple of times before due to high levels of low cloud at the coast.
On the day of your planned flight combine that with the area forecast from NAIPS which, by definition, covers a huge area, and you get a good idea of the overall picture.
Willyweather is also useful for an idea of weather (esp. rain) a few days out, but only covers ground level winds and has no info wrt cloud.
Good luck with your Navs!
Cheers,
Neil