Software
I used to switch between programs, but now I almost exclusively use Mixcraft 6. I find it does everything I need and is a lot cheaper than all the other major music creation and editing programs out there. I use it for both original music and mixing mashups. For original music, I use several VSTs and effects that I use with my guitar (which I'll get into later). There's a few free ones I've found online that I use a combination of that, unfortunately, I don't have in front of me but I have template saved of on my desktop PC that I record with. For the other music tracks, I build them all virtually within Mixcraft. I sometimes use a regular computer keyboard and mouse to create the notes, but a lot of the time I'll use a USB midi keyboard (I even have the keys labeled with corresponding percussion notes).
Instruments
The only real instrument I use is an electric guitar. My guitar is an Epiphone Les Paul. I also have an acoustic guitar I borrow for some tracks but I'm looking at purchasing my own for future music. I don't use pedals or anything anymore since I handle all of that in Mixcraft now.
Equipment
I'm not really going to list my PC specs right now, especially since I sometimes switch with my laptop and plan to upgrade my PC further, but I will say I currently run an Intel Core i5 processor for both running Windows 8.1. Most of my music and mashups are recorded onto a 3TB external HDD which I usually back up... but I've been slacking on that lately. Don't follow that example because if I lose everything I'll be pretty screwed. ALWAYS BACKUP YOUR WORK!
For recording guitar, I use a really old and outdated M-Audio USB interface made to record guitar and microphones. I don't think it's available to purchase anymore since it's been improved upon greatly with new products, but I got it as part of a cheap bundle with Pro Tools. I'm looking at eventually upgrading this one so it's not something I really recommend.
For building virtual tracks, when I'm not using my computer's keyboard and mouse, I use a Korg nanoKEY2, which is great for throwing into a laptop bag. The keys are not quiet but they are slightly pressure sensitive. I even use them to track drums and percussion.
For acoustic guitar and vocals, I use a Shure microphone (not sure which, it was a gift) which is plugged into that M-Audio interface. As a result, there is a little bit of static and some audio issues, but I believe that can be resolved by upgrading to a new interface or mixer. I also edit to make sure it sounds as much like studio quality as possible. I also use a mic cover but as long as you have some sort of pop filter you should be alright.
If you have any other questions, feel free to ask in the comments section, on Twitter, Facebook, YouTube, Tumblr, or Ask.fm!