Passing the Salesforce Platform Developer I Exam
I just passed the Salesforce Platform Developer I exam and here is one weird little tip if you want to pass it too: use this excellent blog post by Snehal Surti, a Salesforce Architect/Consultant in Toronto.
For each topic in the Salesforce Platform Developer I Study Guide (pdf), the blog post provides links to specific resources in Trailhead and the Salesforce documentation. It also has some sage words of advice on things like the order in which to study the topics and how deeply to study them... it's really good.
My two pennies / cents worth: if you've been programming in Apex & Visualforce for a while, you shouldn't need to study too much. It isn't that difficult.
Here is my shiny badge: