let me ask you a question: if you hit the lotto today, would you still want to sign over your rights?
bottom line: babies need their mommies and daddies. they do not need "things". you are young, grant it, but you will not be young forever. also, parenting your child with limited resources is not "ruining him"; it's parenting.
adoption is a decision that should only be entered into because of extreme abuse or neglect. furthermore, there are MANY services that can help you and your gf parent your child, until you all get on your feet. also, you are in college, that is an indication that you have goals and might find yourself in a much better place, financially in a few years.
adoption is a permanent solution to a temporary problem. and there are way too many resources out there to help.
regarding "a better life": you can not guarantee that. just because someone has more money and a nice house, DOES NOT mean they will be a good father. in addition, many people who want your baby chose not to have babies when they were younger, and now they can't. basically, it's not the job of your girlfriend to go through pregnancy and labor so that someone else can get a baby.
furthermore you stated, "I would be considering an open adoption in this case because i can not leave my kid straight up.." then i need to tell you that, OPEN ADOPTION IS NOT LEGALLY ENFORCEABLE. don't allow anyone to tell you differently. open adoption agreements are often used as a "hook" to get ambivalent young people to give up their babies. it is possible that the potential adoptive parents might agree to an open adoption, yet will change their mind. it happens a lot, unfortunately.
honestly, i think you are a bit overwhelmed and trying to make it right. how do i know this? because i was in the same position 19 years ago. and i too made an adoption plan, for all the reasons you suggested. but the closer i got to the date, the more i knew that i couldn't do it. sure people were mad (and some very nasty to me) but i made the best decision of my life.
my son just celebrated his 19th birthday, and is going to college, not in jail, on drugs, or the other things they try to tell you happen to kids with young parents.
also, many parent separate. just because you and the mother will be separated, doesn't mean the child will forever live with two parents. adoptive parents divorce too.
the other part of this is this child's mother. ultimately, she has to agree with the adoption. and if she is not willing to place the child, then no adoption can take place.
also, for every adoptee that is "fine"; there are many others who are not. also adoption involves two mutually different experiences: the loss of a family, and gaining a family. hence, it's possible that even though he might "love" his adoptive parents, he might have a great deal of resentment towards you and his mother. there is no guarantee that your child will understand your reason for placing him; and he might actually grow to resent both you and his mother.
i think you should really just stick around and read stories from women who have been pregnant and made adoption plans. i would also speak with fathers who have placed their children for adoption.
good luck.