YAML Syntax
Here is a partial summary of the YAML syntax you might need, taken from, though you may wish to familiarize yourself with the complete YAML specification.
Integers
canonical: 12345 decimal: +12,345 octal: 014 hexadecimal: 0xC
Floating Point
canonical: 1.23015e+3 exponential: 12.3015e+02 fixed: 1,230.15
Strings
string: foo doublequoted: "Double-quotes allow escape sequences.\u263A" singlequoted: 'Single quotes do not'
Misc
true: true false: false true-y: y false-n: n string: '12345'
Lists and Dictionaries
dict: {a: 1, b: 2} list: [1, 2, 3, 4, 5]
NOTE: the above are also all dictionaries.