How Do I Draw a Pattern on the Computer

[silkpajamas]

I would like to draw a purse pattern and make it into a PDF file. Can anyone tell me what kind of software I could use to make a pattern that won't look like junk? In other words, the lines will be clean, and any labels or instructions will be neat and clear. Something I might pass along or sell. I'd like it to look professional.

Thank you.