When you first visit blockjunkies, you'll find yourself in a building full of information. There are signs to the left and the right on your way out that outline some basic rules to adhere to. Spider webs will slow your exit. (If you missed it, type /spawn).
Along the sidewalk, you'll have a market to the left, and an enchanting/maintenance area to the right. You start with $500 Bucks (our currency) so this is your opportunity to pick up some starter supplies.
Grab yourself some picks, torches, doors, whatever you need to start with at the Market. Starter supplies are to the right on the lower level, while protection stones will be on the left. Typically, you shouldn't even need to buy anything right off the bat because you start with a full set of stone tools, some bread, torches, and a protection stone.
Once you're ready to roll, head into the biomes building and pick a habitat you'd like to build in by right-clicking on the sign warps inside the building. Make sure you travel 20-30 blocks from the spawn building in each biome to make sure you're past the starting region.
Once you find a spot to build, reserve an area for your house. Simply lay down a protection stone and they start working for you. The area inside the glass block field they temporarily generate is your "protected" area. They may take some getting used to, but once you've mastered them, you're grief-proof. Also, if you have trouble laying the stones down, just keep moving around (you're probably overlapping someone else's protection field).
IMPORTANT: After you've got a home setup, please type /sethome to allow yourself the use of /home to return home. We will not be able to assist you if you lose your home.