Music theory may not have been your major of study. One musician to another: we all learned some theory as we participated in music classes, ensembles. We might remember what adagio or lento might mean, but more often than not we’ve relied on the conductor to guide us from the podium. Aspiring musicians can broaden the scope of understanding of what to play from the ink written on the page; to be better players, by deliberately studying elements of theory, like the marks and guidance on the page, in an effort to understand what the composer or arranger had in mind for a phrase. We all learned Pitch and how to create it on the instrument. Meter, Tempo and Rhythm are fundamental elements of theory that are also represented on the page. These enable us to execute as an ensemble of multiple players.
Dolmetsch: An outstanding creative commons resource for music theory is Dolmetsch. If you browse through this link you can find just about anything you are looking for to explain what the markings on the page mean. Click on the link Dolmetsch to explore.
Here is are several quick links for your development:
With specific reference to tempo, here is a link to the Dolmetch online reference. Its a good reference but also a good read.