Originally Posted by: shneeblyWhen it comes to solos in a song, how do you know what notes to use?

If you haven't already, I encourage you to check out Chapter 3 of GF 2 on the relationship between scales & chords.

http://www.guitartricks.com/tutorial.php?input=426
http://www.guitartricks.com/tutorial.php?input=427
http://www.guitartricks.com/tutorial.php?input=428

After that, you'll be ready for these tutorials that are an introduction to improvisation.

http://www.guitartricks.com/tutorial.php?input=876
http://www.guitartricks.com/tutorial.php?input=483
http://www.guitartricks.com/tutorial.php?input=491

There is also a lot of great info on this topic in the Blues & Rock Style courses.

http://www.guitartricks.com/course.php?input=blues1
http://www.guitartricks.com/course.php?input=blues2
http://www.guitartricks.com/course.php?input=rock1
http://www.guitartricks.com/course.php?input=rock2

Hope this helps. Have fun! :)