So, the obvious thing I've found about starters are the following:

1) Yes, they are important.
2) Yes, especially in high gravity beers!
3) Having a starter opens the possibility up of yeast reuse
4) Sanitation is critical.

The less obvious things, I am figuring out. From experience, how can
one tell when a starter is ready to be pitched? After a day, mine has
slowlying rising bubbles. The highly flocculent White Labs English Ale
yeast is sitting on the bottom, fat dumb and happy. Perhaps I should
wait another day...? How should I reuse the yeast? Pour some off the
starter into my White Labs vial? Take some from after the primary
fermentation? (If so, how do I avoid sucking up a bunch of trub??) Is a
1000mL starter good enough for a 1.090 SG beer? If not, I guess I need
a bigger Erlenmeyer flask!! Does the yeast change/mutate/grow "tired"
after a while and if so, how does one avoid that? People used to make
beer without yeast. How long did it take to get the wild yeast in
there? How the crap did they make any heavy beers? I've heard an
anecdote about Vikings with big family yeast sticks... Is that whats
going on?

Steve