You get free boots at 10 min. but you cannot buy boots before then. These boots give additional MS. For each takedown you acquire the boots 30s sooner.
Offense
+1-10% CDR
Flex
+6 Armor
Defense
+15-90 Health
WhyGuardian
Guardian synergizes well with Taric's [W] when looking to block big incoming damage and the extra burst of Movement Speed allows your to position yourself to land [E].
WhyShield Bash
Shield Bash is easily proccable with Taric's [W] and synergizes well with his passive when looking to offensively auto attack in fights.
WhyConditioning
Conditioing on Taric makes you a big front-line tank in the mid-game and your natural synergy with Armor will make you and your linked [W] ally difficult to take down in skirmishes/teamfights.
WhyRevitalize
Revitalize synergizes well with both [Q] healing, [W] shielding strength, and Locket shielding making your teamfight damage mitigation incredibly strong.
WhyBiscuit Delivery
Biscuit's massive mid-fight health regen when you are below 50% will allows you to absorb a ton of poke and front-line damage thanks to your natural high resists.
WhyMagical Footwear
Magical Footwear is an all-around good rune choice on nearly every champion. It act effectively as a free kill's worth of gold at 10min allowing you to hit your combat stat item pokwer spikes even sooner.