How do you interpret weather reports when considering a cross-country flight?

Spring is getting near. I want to learn cross-country flying. I want to do the 50 km flight for the Silver badge.

Here’s the first option I’ve looked at: http://www.nscale160.com/xc/

Bermuda High (SC79, 550' msl) is 34 nautical miles west of the Marlboro County Jetport (KBBP, 147'msl). Using the “one percent rule” I can’t release any higher than 1390' agl at Bermuda High if I'm simply going to land at BBP. I understand if I use a logger and arrive high enough over BBP before landing that I’m OK...

I suppose I could release higher, descend below 1390' agl in a good thermal and then climb again and fly on. Hmmm.

If you look at the screen capture map on my website you'll see my initial idea. If you have any feedback on the route(s) I’d be interested, but that's not really the purpose of this post.

I’d like to learn more about weather forecasting/understanding/planning or something like that.

What are good links to places you use to check the weather?

How do you know from looking at the weather that "today's a great day to try a 50 km flight"?

Thanks in advance.

Terry