Well I'd also reccomend a corn, but not a carpet. Those are a little more challanging to keep, I wouldn't say for a first time keeper to get one. They also grow upwards of 10 feet (or so i've read.)
Since you are new, i'll give you a little info of what i'll refer to. Snakes defenses go in the following order. 1) stay perfectly still and hope they're not seen. 2) run away. 3) rattle tail. in dry leaves (as it would be in the wild) they can sound like a rattle snake and scare off would be predators. 4) closed mouth strike. 5) open mouth strike.
Corns, or any north american rat snake for that matter, would make a great starter snake. Or a kingsnake/milksnake.
I'll give you a very brief rundown on what I have experience with. On those I don't list... people don't get mad at me here i just dont know enough to give an accurate synopsis of the particular animal. this is where you can chime in 
Rat Snakes:
Corn Snake - grow 4-6 feet long. handle well, mild tempered. Occasionally you'll get an agressive one, but 99% can be tamed to be very calm within a relatively short time frame. Lots of colors, readily available (every time i say this i will be referring to the US), and if you get one from a particular breeder they can tell you more about the specific snake, personality wise.
Texas Rat Snake - grows 4-6' long. tend to have a little more attitude to them. Mine loves to rattle his tail, yet has never struck at me. Some like to bite, some don't. All snakes are different, but I think these tend to be a little more wild.
Everglades and Yellow Rat Snakes - Both grow about 4-6' long. I have never had one, so no first hand experience. Others please chime in. I've been told by some that these two are somewhat agressive, however others have told me they're very docile. I have come to believe they are very similar to a texas rat snake as far as agression goes.
Gray rat snake - kinda boring IMO. They are going to grow 4-7 feet or so, and seem very docile. Even the wild ones around here that I have found have never struck at me. These interbreed with yellows or glades (dont remember which) and are labeled gulf hammock rat snake. then another morph would be a oak rat snake.
Black rat snake - another one of my favorites. Growth 5-8 feet. you can get them in all kinds of color morphs... from orange albino to white sided, ultra jet black, the one i'm going to be getting this summer is called a grape albino. lavander patches with white inbetween. I also have a regular black rat and a licorice stick (whitesided). They are both very docile, never struck at me. Never rattled their tails.
Kingsnakes/Milk Snakes
I have never had either of these (they are in the same family), so i can use all the input on these.
Kings and milks are both cannibalistic. That's one place they get their name. They are capable of killing and eating any other snake, including a rattlesnake. Therefore, never house them together. Never house two snakes together actually, not a good idea. Cannibalism can happen in any snake.
They grow from 4-8 feet or so I believe, depending on type of snake. Good eaters, and easy to handle. they can be kinda nippy as babies (but so can the rats. forgot that.) i've had some tell me that they're a little more challanging to handle, others tell me that they're just as easy. If these interest you, i'd ask over on the kingsnake forum.
I'd go to google, type these types in, get some info, see which ones interest you. Go to the specific forum and ask away 
Also, you mentioned you don't want a constrictor. Sorry, you're out of luck. To my knowledge, the only two types of snakes in that respect are constrictors and venemous. and trust me, you don't want a venemous as a beginner. Hell, I don't want a venemous! i don't trust myself!
On that note...remember. you can lie to everybody but yourself.
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Chondros and colubrids... my 2 favorite types of snakes!
"Life is hard. Life is harder if you're stupid." - John Wayne