Another thing I’m constantly Googling myself silly over are the HTML codes for special characters such as Registered Trademark (®) or feminine Ordinal (ª). Here are a few more and a link to a massive list of them.
&ndash ; – en dash
&mdash ; — em dash
  ; nonbreaking space
¡ ; ¡ inverted exclamation
¢ ; ¢ cent sign
£ ; £ pound sterling
¤ ; ¤ general currency sign
¥ ; ¥ yen sign
¦ ; or &brkbar ; ¦ broken vertical bar
§ ; § section sign
¨ ; or &die ; ¨ ; ¨ umlaut
© ; © copyright
ª ; ª feminine ordinal
« ; « left angle quote
¬ ; ¬ not sign
­ ; soft hyphen
® ; ® registered trademark
¯ ; or &hibar ; ¯ macron accent
Many more to be found here – Wired WebMonkey