Welcome to Oppo! This post is a short guide on posting pictures on Opposite Lock. As an example, I posted one of Oppo's most beloved vehicles - the Chrysler Sebring convertible. It even fits today's theme - Tan Tuesday! More on themes in a minute.
There's two easy ways to add pictures to your post - one is to upload the picture from your hard drive, and the other is to use a direct link from a webpage (direct links end in .jpg, .gif, .bmp, or similar formats - direct links do not end in .html). You access both of these options at the top of your post, using the 4th icon from the left (the picture icon).
Uploading from your computer is convenient, but depending on your web connection it can be slow. What I generally do is upload pictures to a free image-sharing service (I used to use Photobucket exclusively, but now use a combination of ImageShack and Imgur), and then use the direct link from the image-sharing site. This allows me the convenience of being able to upload at a lower resolution so I don't brutally sodomize anyone's Internet connection.
EDIT: Thank you to Victorious Secret for the following tip - Kinja likes to crop the bottoms of pictures. To avoid this, upload any picture you want to post to Imgur and then use the direct link from there.
Theme days are when several long-time commenters agree on an overarching theme for posts they'd like to see today. They usually use some form of alliteration (Mopar Monday, Tan Tuesday, etc.) but not always. You don't have to explicitly follow any theme days, but you'll get more comments on your pictures when you do.
This isn't specifically about pictures, but it is about posting. On the left hand side when you're making a new thread, there's a spot that says "Publish: Now" with an arrow next to it. If you click on the arrow, it brings up a menu that says Now (when you hit Publish, it goes live right away), Draft (never used it), and Scheduled (the option we want). When you select the scheduled tab, it lets you choose a date and time for your post to be published. This defaults to the current date/time at Jalopnik HQ in New York. This is a convenient option if you found a great picture in the middle of the night, but wanted to post it in the early morning when Oppo is most active. It's not a feature you need often, but it's good to know how it works.
So, have fun out there! And remember, Oppo also loves rotaries!