Characters that don't occur on the keyboard need to be copy-n-pasted. Characters I use frequently:

description	copy/paste	HTML entity	URL encoding
em dash	—	—
	←	←
	⇐	⇐
	→	→
	⇒	⇒
dagger	†	&dagger;
double dagger	‡	&Dagger;
right paren	)		%29
transgender symbol	⚧	⚧

generally useful (copy/paste only)
- @wikipedia
XHTML character entities
- @digitalmediaminute.com
- @elizabethcastro.com
unicode charts
- @itnewb.com
- @fileformat.info
- @DecodeUnicode
- @alanflavell.org.uk
- @wikipedia
- @aleto.ch
- tomw@wisc.edu
- unicode spaces [1] [2]

Bullets

•	U+2022	BULLET
‣	U+2023	TRIANGULAR BULLET
◦	U+25E6	WHITE BULLET