Yamaha DTXpress/DTXplorer/DTXtreme

Dear All ,
I'm the new boy of the group !!!
I have owned a dtxpress for about a year now and spent very little 
time reading the instructions when I got it and just got down to 
business. Brilliant fun !!! However , I now want to start messing 
around with writing music and so I have the following two questions 
which I hope one of you might take the time to answer :-
 
1. What affordable music making software do you recommend to start 
off with which allows you to create your own riffs , solos etc but 
also has various preset riff patterns ? ( I have the Music 2000 cd 
which was bought for me and is a bit fiddly , I have the Sound Studio 
Pro on demo at the moment which seems really good and I have read the 
reviews on the new Magic Mix 6 which sounds interesting although I 
think it is more of a musical jigsaw where you insert preset 
patterns. )
 
2. How do I record my dtxpress on to my computer ? Are there special 
leads ? Is there special software that I need ? ( Sorry , I'm a bit 
thick when it comes to computers )  
 
Anyway , here's hoping that one of you gets back to me. 
 
Cheers 
 
Andy