There is a whole forum talking about this and also Clay Davenport has a great website that helps with it. http://www.arbreptiles.com/index.html (on the right side there is a bunch of cage building info)

I am planning on building a 3x2 and will be staining all pieces on all sides. I will probably let cure for 3-5 days depending on temperature and do 2-3 coats of stain. After staining I will polyurthane seal with same cure time and do probably 3 coats of that.

Its a long time to wait but think about it in proportion to how much time your snake is going to spend in it. if it takes 3 or 4 weeks to build the cage and the snake is in it for 2 years. Thats 104weeks usage to 4 weeks building. not half bad in my opinion. Besides if your going to be building a cage you probably want it to last more than 2 years.

I guess my advice is be patient and let it cure for a long time. Maybe double whatever the bottle says.