These items are pretty standard on Kaolin, gives him early damage and hp, and quickly solves his mana hunger problems, while serving as a bridge for late game core tank-bruiser items.
Start with the second starting option if you feel like you're going to face a lot of harass or if you're somewhat new to this hero.
Skills, combos, and boulders.
Always pay attention to your boulders, they are the core of your skills. They don't give vision but you can cast them from a huge range without vision as a requirement. For your E, remember to always put it in front of your enemy's escape route to assure that you stun then and they can't escape.
Your Q isn't useful in the early game and is only useful as the coup de grce of your combo, so we'll take an early point at level 3 and max it last.
Max your E first for the Boulder -> E early stun combo to harass and keep targets from escaping, and W afterwards to deal damage.
By the time you're level 3, you should be familiar with this basic combo:
Boulder in front of enemy -> E on boulder to stun -> Roll -> Q into your tower or the opposite way to prevent your enemies from running away.
When you already have your Drums/Perseverance/Bloodstone/Blademail, mana shouldn't really be a problem. By the time your W is maxed, you'll have a 4 second cooldown and you'll be able to Boulder->W your way around the map constantly. Remember that your W will go through unpassable terrain while in full speed, so time it correctly or you'll end up trapped, stomped against a wall and/or dead.
Your ult should be used mainly in teamfights after quickly spamming the area with your boulders to build perimeter where your enemies can't escape without being dealt damage.