There are no stupid questions. We all get stuck sometimes!
Personally, I find seeing a problem on an actual web page easiest to debug. I can use the browser's debug tools (like Inspect Element and the like!) to instantly see why something is behaving the way it does.
If it's not online yet, copy-pasting the code into a [code]...[/code] block is second-best. It's much easier to read code when I can highlight it, copy-paste bits into another file, etc.
Working from a screenshot of code is hardest. After all, the problem might not even be in the bit that's in the screenshot! Maybe there's a stray bit of CSS somewhere that's affecting the problem element? Or maybe there's an element that didn't get closed properly half way up the page! This makes working from screenshots of code very hard!
So in short - for me at least:
1. A link to a broken web page is easiest to fix,
2. The code from a broken web page is next-easiest,
3. A screenshot of broken code is pretty difficult, and
4. A description of the problem with no context at all is a BIG challenge! (you do see people who say e.g. "my page is broken but it was fine yesterday; what changed?" and give no clues at all!)