Unless you get the Jumbo varieties they are all sort of puny looking. ABout the diameter of a fat finger at best. The jumbo varieties actually come as nodes.
Sometimes you can force more shootlet growth off the new rhisome by placing them in a dark, warm closet but it really is better to get them in the ground as soon as you can because they will start to deplete stores and need to replace those nutrients.
There are, at the least, two main schools of thought on bine selection.
The first - Clip off all bine growth until a few weeks after the last frost. Then let them all grow until they about a foot long and choose the fattest, healthiest, longest bines for training and trim the rest.
The second - Trim nothing until they are all a foot or two and then choose the fattest, healthiest, longest and train them.
The former is intended to force th plant to produce better bines while the latter promotes a smaller time frame to allowing the plant to start photosynthesis.