This forum is fine although "how-to questions" would be good, too.
What you are experiencing with the ribbing is very common. When you make a purl it uses more yarn so it stretches it out as I understand it.
There are a few different methods you can try.
1. Use smaller needles for the ribbing
2. Wrap the first purl stitch the opposite way (under not over)and then knit into the back of the stitch on the other side because this creates a twisted stitch.
3. Try Norwegian purling
for that stitch if you're a continental knitter (yarn in left hand).
If you're knitting in the round you can try my method.