This is from my wife!
1. Wait until you are married and enjoy a couple years of just being two! This will strengthen your bond with each other which will really help when you have a baby in the house.
2. If you have any plans to further your education wait till that is done at least as it is very difficult to write a paper at 2:00 AM when your baby is sick.
3. All the help in the world is great, but grandma may not be very happy with you dropping the baby off with her while you go to a concert or a hopping club.
4. My wife was 31 when we had our daughter. It has been great and the added finacial security you develop in this time can greatly reduce stress you may encounter at a younger age when you are counting pennies for diapers! Trust us they go through diapers like the Government goes through money.
Our general opinion is it would not hurt to wait until you are at least in your mid to late 20's as it gives you a chance to be you instead of being for the sake of a child, or so it seems. You just became an adult figure out what you want to do for the rest of your life. Being a mother or father is a noble thing when taken seriously, but it can easily take away your true identity! (i.e. my wife is known as my daughters mother in the circle of kids and the parents of the kids my daughter plays with!)