I just found this adorable blog called A Cat Of Impossible Colour. She did a series of blog posts about a year ago talking about thrifting and getting into vintage thrifting. I found it so helpful!
Here are the posts:
Part 1: Getting Started
Part 2: Finding Treasures
Part 3: Spotting Vintage
Part 4: Cleaning & Caring for Vintage Items
Part 5: Incorporating Vintage Into Your Wardrobe
I can't wait for March when I can go back to thrifting! I've missed it a lot.