When a pattern asks you to "pick up 3 stitches every 4 rows" does that mean that you pick up 1, 2, 3, skip then start again by picking up 1, 2, 3?
I know this might be basic, but I never seem to 'get' this concept thus, I pick up too many stitches or too little. Can anyone help?
Yes, you've got the right idea: "...pick up 1, 2, 3, skip then start again by picking up 1, 2, 3..." That'll keep you approximately on track to pick up the correct number of sts over the entire length. In other cases where you aren't given this helpful instruction, you can mark off the length into halves or fourths and pick up sts in each shorter section.