By far the most commonly over looked part of keeping venomous snakes is... BASIC HUSBANDRY.
Make sure you are 100% comfortable with routine procedures, how to manage a sick snake, how to deal with non-feeding snakes, how to medicate snakes. Many people jump into hots way too quickly. Some people will have no prior experience with reptiles, and some think they are ready because they've kept a blood python or two and a corn snake.
It isn't uncommon (unfortunately) to hear from people that aren't even sure what kind of venomous snake they have, what AV to use, or what could result from a bite.
Keep and breed various nonvenomous snakes first. Get all aspects of husbandry under control. Then think about finding a mentor.
As far as prepping for keeping a mamba, an asian ratsnake won't do it. Years and years of venomous experience, after years of nonvenomous experience is the only appropriate way to make it up to keeping such a snake.
In short, just take your time, and don't be the guy that posts "Hey, I've got a cobra, what do I do now?" and "What's a hide box?" and you'll find there are lots of people in this community that are willing to help out someone who genuinely shares an interest in the husbandry of venomous reptiles.