There is an endless amount of addons available for World of Warcraft, and while I encourage you to experiment with your own interface setups, I wanted to write an overview of some addons I use as a starting point. Feedback is appreciated, you can tweet @Daemagor or leave a comment below.
WeakAuras (Spell Alerts)
I use WeakAuras to give me additional visual cues for spell cooldowns and durations.
WeakAuras makes it easy to export and import auras. Type /wa into your chat, click on the New button, then on the Import button, and paste any of the import strings from the links below into the box.
Tal's Mistweaver Monk HUD
This HUD tracks cooldown and duration information for many Mistweaver spells. From the author's page:
Above Main HUD
Teachings of the Monastery (Middle)
Lifecycles Vivify (Left)
Lifecycles Enveloping Mists (Right)
Icons Main HUD
Thunder Focus Tea
Sheilun's Gift (=4 Saturated, >=6 Glow)
Essence Font Tracker (This is only available in a group situation where it is able to track players so you can judge the effectiveness of EF)
Focused Thunder Stacks
Rising Thunder (Tracking Rising Sun Kick)
Life Cocoon (Left)
Refreshing Jade Wind/Invoke Chi-ji/Jade Serpent Statue (Right)
Chi Burst/Zen Pulse/ Mistwalk (Right)
Tal's Mistweaver Monk CD Bar
This bar tracks several ability cooldowns not tracked by the HUD above. From the author's page, the bar tracks the following abilities:
Ring of Peace
Song of Chi-ji
Perfectly Preserved Cake
The Perfectly Preserved Cake tracker shows how many plays are in range of you and will gain the shield, as well as the cooldown of the trinket. You can get the import code for the Cake tracker here.
Ornate Spell Trackers
The ornate spell trackers show the duration of Invoke Chi'ji, Blessing of Yu'lon, and Mana Tea. These aren't entirely required as they're tracked using the other auras above, but they add a bit of extra thematic flare to your UI if you like that sort of thing.