I have a Software question..

So, I hand draw my models (already a problem since my handwriting is terrible), but to make them accessible to you guys I have to take a pic of it and convert to a pdf. This results in a lesser quality and a very blurry blot for landing gear. Is there software where I can scan my plans and draw over them and neaten them up, type the words, and have a sharper, not-dimly-lit plan like the pro's? If so, which one do you recommend and how easy is it to use? Thanks in advance to all who help. And btw I have a Dell laptop with Windows 8