If you're new around here you might appreciate browsing through the submission history of a few of the legendary builders:

/u/HiddenWorm shared with /r/Minecraft awesome build guides for all sorts of useful topics:

• Gothic Cathedral Guide

• Greek Temple Guide – relevant for the current /r/Minecraft build theme

• Monastery Guide

• Many many other useful posts on design tips, and architecture elements – like this fortifications guide.

/u/Sarlac was one of the 2015 /r/Minecraft Best Of winners:

• Minimalism Guide

• Bridges

• Responding to Terrain

• Many many more guides

/u/MCNoodlor, also an award winner, makes proper in-game scale creations that fit the Minecraft design sense so well I won't be surprised to see his work in the vanilla game one day:

• Fortified House Guide

• House Planning Guide

• Many more excellent inspirational examples and world downloads to explore up close

/u/Hyta for massive procedural architectural marvels including script samples:

• The Gherkin

• Tower of Babel

Also consider exploring the /r/Minecraft/wiki which has pages on reference builds and design tips for you to find inspiration within:

• /u/Sarlac's combined guides

• Builds

• Details

Enjoy!