My favourite site for charts a few days in advance is:
http://expert.weatheronline.co.uk/
In particular, the model overlay chart is excellent at working out whether any forecast for a particular day is likely to be of any use: if all the models have very different views of what's happening, you know you'll just have to wait and see.
The site has a huge range of charts derived from the GFS model, though there's not all that much to help you with cloud cover.
Mark