You should talk with a lawyer about any specific legal issues as they are the only people who can offer proper advice.

However, with regards to using music in your films, you are only able to do this for your own personal, private use. You are not allowed to show your films to any audience (whether they pay or not) if you use copyrighted music without first obtaining the appropriate clearances. So showing them at your school or putting them in a theatre for a public display is illegal until you obtain the rights to use the music you have selected.

filmmaking.net

In response to:
Do you know the exact copywright laws on music? I always copy music and use it for my trailers and films, but only for home entertainment. Soon I am going to be making shorts on a good camera and about a $2,000 budget. I got a good job. I also plan to rent out theaters and premiere these films to the public. Seeing as hopw everyone in my school is anxious to see my material.

Again I was curious on the EXACT copywright laws. If you could tell me, or if you have a link, I would greatly appreciate it.

Thanks.

Joshua

In response to:
You can use Sound FX from other movies. Doesn't matter what movie it is since you cannot copyright them. That does not include music but it helps when needing a certain sound that you've heard before in a movie but aren't sure how to recreate.