So, you would like to know how to make music beats using your
computer? Well, I can help you in that subject because my brother is a
known DJ and has created tons of music beats. He now has a studio, but
in the beginning, all he had to make a beat was his computer. He had
no instruments either. He used to make instrumental on his
computer. After what he taught me, to create music beats, you need to
have three things. You need to own a program which can create
beats, patience and creativity.  All the rest (notes, key pads,
creating the sounds...), you can learn from the instruction manual you
get with the program. It is really easy. All you have to do is read!
First of all, to make your beat using your computer, you need be the
owner of a program. If you are not, then you can buy a program almost
anywhere. Most of them are sold on the internet. The best price range
for a program is from 25$ to 45$. You should not buy a program that is
more expensive than this range. A lot of programs are expensive
because of their Brand.     Secondly, you need to have
patience. It takes patience to make an instrumental. If you quickly
make an instrumental, your creation will not be good. When you take
more time, more ideas come to you. Also, when you are on the computer,
you can take ideas from other beats. Do not forget that you cannot
copy them!   Finally, you need to have creativity. If you are
making a sad song, then click the pads (comes with the program) that
have soft notes. It can be the piano notes or the violin ones.
 The emotions of your song have to go a long with your beat. Just
by hearing the beat, a person should realize that this song is going
to be a sad one.

http://groups.google.com/group/sonicapro/