Using Melody Assistant
Music notation is easy, you just need to know the symbols and what they stand for.
The Time Signature, it's the number of beats in one bar. 4/4 means four quarter notes in a bar and 3/4 means three quarter notes in a bar. So a bar with 4/4 time signature could contain one whole note, two half notes, a dotted half note plus a quarter note. It's all about duration, you can always try a quarter note first, if it's too short then try a half note.
Chords are three or more notes that are played at the same time, they are necessary for your background music. You should at least know how to play a guitar because background music just depends on chords, for the bass part and the guitar part.
Tempo is the speed of the music, so it makes sense to write first your drum part with the closed hi-hat as your beat/guide.
Melody Assistant can load Midi files (*.mid) and karaoke files (*.kar). If you like to have fun, you can download them, Midi files with lyrics will be automatically sung by Virtual Singer.
You can use Melody Assistant for free, you can write and save although to use its features fully you need to register your copy.
http://www.myriad-online.com/en/products/melody.htm
http://sharebee.com/08e23d7a /Sweet Fire Burning.myr