Golden Shovel
The golden shovel is very easy to gain, all you have to do is bury a normal shovel for 24 hours. When you dig it up again after this time it will have turned gold!
Golden Net
Catch every bug at least once and Tortimer will give you the Golden Net.
Bug Guide

(click image to enlarge)Golden Fishing Rod
Catch every fish at least once and Tortimer will give you the Golden Fishing Rod.
Fish Guide
Golden Slingshot
Shoot down 15 balloon presents from the sky. Then the 16th balloon will have a Golden Slingshot attached to it.
Golden Watering Can
Have a perfect town for 14 days and then when you next talk to Pelly or Phyllis they will give you the Golden Watering Can.
Perfect Town Guide coming soon.
Golden Axe
Give a Scallop to Pascal and ask for the Golden Axe.
Red Turnip Trade guide