Snip*
Full Value - does that mean a straight 90 degree cross wind?
Yes. Here is a good
article on wind basics. Has a chart, I printed a small copy and taped it to my buttstock along with come ups for the different yard lines with clear packing tape until I had it all memorized.
Look at the chart labeled clock system to see what the different values are, learn the angles by clock position, same way we call round impacts on target. Notice a half-value wind is not exactly 10:30. don't get too wrapped up in precise reading of the wind angle at first, just get a good idea what full, half and quarter value is by looking at the wind flag angles. Learning the flags as well as reading mirage through your spotting scope will come with time and you will develop a system to determine wind dope with each shot as skills improve.
Takes a few seasons to figure it out confidently, try and shoot when the wind looks the same each shot if possible. Watch other good shooters, they are great for judging wind when you score for them. Ask them when they are done firing what the wind was worth (in minutes) and pay attention to what conditions they fired mostly. Laminated wind charts for the bullet you shoot are available or make one. Comes in handy for making a guess what windage to put on when it's time to shoot.
I still make notes while at different ranges such as how the wind acts due to terrain features, lighting, altitude ect. That's why a scorebook is so important when starting out. Keep records of the things you see and do by writing it down after shooting a string. I just use a pocket pad kept in my shooting cart.