Hi Nina,
I purchased a software program called PC Stitch 10 and it's so much fun to use! It has tutorials on using the software and even helps you create your first pattern. You can scan photos and then upload them into the program or just start from scratch. There's a help section that answers a lot of your questions. I would highly recommend it if you are seriously thinking about doing your own patterns.
You can find in on the internet, just type in PCStitch10 and it will take you to different places where you can purchase it.
If you have any more questions, please feel free to ask. I'd be glad to help.