Ok- let me start by saying that this is my just my opinion.
There are plenty of great snakes to start out with. Do a search on the forums and this question gets asked all the time. I personally don't think Blue Beauty snakes are a good beginner snake. They are one of the bigger colubrids and tend to start out as fiesty little buggers and can grow up to be big fiesty snakes. The feeding response of Beauty snakes is generally VERY strong. When my male Taiwan Beauty eats (he's 7.5 feet and 10 yrs old) - it's serious business and you'd better have some tongs to present his meals with because anything is fair game when he's hungry. I raised him from a hatchling and he's always been one of my favorite snakes but he scares most people because he's large and usually looking for food. I don't mind using a hook to move him out of the cage but some people might not want to deal with that.
The other snakes that people have recommended to you are good starter snakes, North American rat snakes (including corn snakes), king snakes, and garter snakes for example. They all have different requirements depending on the species. Garters are neat, but most eat fish unless you can get them switched over to mice (usually by scenting with fish).
My personal list of good starter snakes would include any of the North American rat snakes in any of the color varieties (albino, leucistic, brindle etc,...), Mexican Black King snakes, Mexican King snakes, California King snakes, Sinaloan Milk snakes, Garter snakes of the many varieties, if you don't mind possibly feeding fish to them. Also, African House snakes are a little different and easy to keep. There are care sheets here on Kingsnake.com that will help you out with caging and feeding requirements. What ever you decide, I suggest not keeping two snakes in the same cage other than for breeding introductions. They might tolerate each other or they might totally stress one another. It is much easier to monitor the health of a single snake in a cage and if one of the snakes is sick or becomes sick- you have less worries of transmission.
Check out the classifieds for different types of snakes that are available and you'll find that "uncommon" snakes tend to have a higher price tag and more stringent care requirements. You can also see what the snakes look like if the sellers post pics. Also, check out the different forums (like you've been doing with the rat snake forum) for snakes you're interested in. Be sure that on most forums if you ask "Is this a good snake to get" most people on that forum will tell you yes because that's what they've got.
Most small/juvenile snakes do well in a small cage to start out with and you move them up into larger cages as they grow. Keeping a small snake in a small cage means that they don't have to go too far to find their water dish and hiding places. When you feed them, same thing, you want them to find the food quickly so you feed them in small containers (like a small paper bag or a deli cup). In nature, small snakes have to hide most of the time or they'd get eaten. If you put a small snake in a large cage- good luck finding it most days. Again- this is just my opinion. With the escape issue, any snake of any size will explore its cage. If there's a way out- it will find it regardless of cage size. Snakes in the wild move from place to place till they find food or shelter or a mate. Snakes in a cage will move about as well, searching for these things and if there's a way out- they're out. No psychology involved, it's just what they do. The goal is to provide a habitat for the snake that will meet their needs for food, shelter, etc,... within the confines of the cage. They'll still escape if there's a way out of the cage though, so escape proofing the cage is crucial (see the escaped snake forum for stories about this).
Don't limit yourself to just what's in the petstore this week. You may want to take some time to be sure that the snake you get is really something that interests you. If there are any reptile shows in your local area, they're a great way to see tons of different snakes and talk to the breeders about their care requirements.
Hope that helps.
Lora