I want to begin to learn music theory, so can anyone tell me where to start learning music theory.
^Her sig, or better yet, try to take a course in college/high school or find a private instructor. Makes the road a bit smoother and makes sure you have few if any gaps in your fundamental knowledge of theory.
If you're in college and need to meet an Arts requirement or just need some free elective credit, take Theory 101 or whatever your school calls it. Likewise, consider taking AP Music Theory if your school offers it; you should be warned that the class is not easy like most other high school arts classes.
this, along with this