Audacity. You've probably heard of this. But if not, Audacity is free software that allows you to record sound, using a mic or whatever's playing on your computer. It also allows you to make adjustments to what you record, such as changing pitch and amplifying your sound. Personally, I use it to record some of the radio shows that I present on, so that I can trim and adjust the recording, and then upload it as a podcast.
FL Studio. If you're into making your own music, this is the best software to get. A lot of the pros use this to create instrumentals for songs because of the amount of control it gives you over the endless sounds that are available. It's a lot to take on at first, but once you know your way about it, you'll love how it works. It also records vocals, so you can create an entire song just using FL Studio. Personally, I use it for to manipulate my voice to create a good jingle for my radio shows.
VideoPad Video Editor. As you probably guessed, this software is for editing software. Even though it's not the one the pros use, I find it works really well and is really easy to use. It's so easy to use that I seem to know it well, but I've never watched a tutorial. For the pro software, I recommend Adobe Premiere and Adobe After Effects.
Virtual DJ. Back to music, this software is used by pro DJ's because it allows you to manipulate music while it's playing, which is great for mixing it up and creating a better atmosphere if you're in charge of music at an event or party. Personally, I sometimes use it for my radio shows because it means I can plan a whole radio show on it before I go into the studio. Plus, while the show is LIVE, it means I can fade songs and wind down the volume when I need to talk on mic. It's also great for home use, letting you create playlists for when you're working or out and about.
Photomatix. Lastly, I'm going back to photography by telling you about Photomatix, which is an HDR piece software. If you're serious about photography and like to experiment with different styles and projects, you'll love how this brings out the detail in your photo. So much so that it's nothing like the human eye can see, and you'll fall in love with the HDR quality it gives your photos. What's also great about it is that it gives you the choice to bracket your shots (merging more than one exposure), or use tone mapping (using just one shot.)
I know this is all a lot to take in, and it's impossible to learn all at once. Though, I strongly recommend that you try them one at a time and see what suits you and what doesn't. I'm still learning, and the main thing is that I enjoy it, so don't stress out and always stay original and creative.