Upgrading 6.5.1

I've just been asked to upgrade a postgres 6.5.1 installation. The DB is
very simple with only one large table (really bad design, but my job is
just to upgrade the software, not touch the design, thank God).

6.5.1 is *really* old. Are there any docs still left lying around on
things I should watch out for (data types that are no longer supported
for example) when moving the data? Or is it as simple as doing a pg_dump
of the old DB and loading it into the new one; I'm assuming there *is* a
pg_dump in 6.5.1?

Also, assuming we run the new version on the same hardware what kind of
a performance increase should I expect to see. Maybe about 20x faster?

Thanks!

Jc