Building your own desktop isn’t as difficult as it looks—it’s often called “LEGO for adults.” And while that phrase might be a bit condescending (adults can enjoy LEGOs too, ya jerks), it’s not wrong. Even so, the sheer breadth of choices, options, and compatibility issues can be intimidating, especially for a first-time builder. Here’s a collection of online tools to help you make sure that process goes as smoothly as possible.