I agree with Jeff, make sure you read everything you possibly can before bringing home a rainbow. Do you have the cage set up yet? If not, have it up and running at proper humidity and temps for at least a week before you bring home your snake. I also use a 29 gallon aquarium (with a glass lid) for my BRB juvenile, and getting the temps and humidity to balance took a lot of tweaking. It was more difficult than I expected.
I started with a BRB as my first snake, so it can be done, but like Jeff said, you have to be the kind of person who loves to research and learn all you can. I read through all the posts in the forum here several times, as well as all the yearly archives before I decided on my BRB, and I still have trouble knowing what to do/how to react to situations most of the time.
It's a constant learning process.
BRB's require very close monitoring of their temps and humidity. If you're a busy person and don't have much time to check on your snake often, I'd go with a less demanding species. But if you have the time to research thoroughly and keep a watchful eye on your new snake, a BRB could be right for you.
Personally, I was positive that I would be ready for my BRB as a first snake, since I researched so much for over a year. But still, after getting her, I do wish that I had started with something a little easier. She is beautiful, gentle, and a joy to keep, but I think that easing myself slowly into the hobby would have been less stressful.
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::i believe in joy > http://www.winds.org/nekomi/hope.html
::my homepage > http://www.winds.org/nekomi
My Growing Zoo:
1.0 Husband (Byron) ^_^
0.1 black cat (Shade)
0.1 Brazilian Rainbow Boa (Zia)
1.2 Cockatoo cichlids (A. cacatuoides yellow-gold)
1.1 WC Cockatoo cichlids (A. cacatuoides blue Peru)
3.3 Pygmy corydoras (C. pygmaeus)
2.0 Endlers' Livebearers (P. sp. Endlers)