Note that macros != templates

Good call, @chris-morgan and @cmr!

src/doc/guide.md

@@ -200,7 +200,10 @@ The second point is the `println!()` part. This is calling a Rust **macro**,
 which is how metaprogramming is done in Rust. If it were a function instead, it
 would look like this: `println()`. For our purposes, we don't need to worry
 about this difference. Just know that sometimes, you'll see a `!`, and that
-means that you're calling a macro instead of a normal function.
+means that you're calling a macro instead of a normal function. One last thing
+to mention: Rust's macros are significantly different than C++ templates, if
+you've used those. Don't be scared of using macros. We'll get to the details
+eventually, you'll just have to trust us for now.
 
 Next, `"Hello, world"` is a **string**. Strings are a surprisingly complicated
 topic in a systems programming language, and this is a **statically allocated**