I was wondering if someone could tell me the correct format for writing signs in the work? I noticed that Stephen King capitalises his signs (e.g: KEEP OUT!) but the font seems to be slightly smaller, and I can't tell if its a completely different font from the main body. Thanks so much
I'm not sure there is a "correct" format - just whatever will make it clear that you're writing a sign. I'd be careful about playing around with fonts - if you're self-publishing you'll be looking mostly at electronic sales and e-readers are not known for their ability to accurately reproduce subtleties (they're more about customizing the display to reader preferences). And if you're looking for a publisher they'll have their own ways of handling things and you don't need to worry about it. I'd say all caps seems effective, unless the sign is super-long, in which case maybe you'd want to use some sort of indent or other block quote feature.
I'd be inclined to just interpret it in speech 'Bob looked at the sign "Beware of the leopard" he said "that's welcoming" '
That's a reasonable enough way to do it. Honestly you can do this stuff however you want; all caps, no caps, in speech, or treating signs as more generic (ie "a keep out sign" instead of "the said said KEEP OUT"). If you have a specific way that you like to do it then that's probably fine and it's not really a contortion of your writing to put signs in whatever way you feels works best. Just as long as you are consistent in style then it's not something to worry about.
Personally, I'd italicize it. If you make the call that you capitalize signs, then you have to maintain that all the way through, even if the sign itself is not capitalized. This allows you to have the context the sign is trying to present too. To me there is a huge difference between Stop here! and STOP HERE!
Just for a chuckle. I did just see a sign that read: THIS SIGN IS NOT IN USE It was sitting beside the motorway—nothing else around. I think I know what it's for, but seeing it sitting there on its own did make me laugh.