autovacuum settings

I am totally new to postgres and I wondering what settings should I be
using for autovacuum ?
For now I just uncommented all the defaults, is this good enough ? The
database is not large but it is a web database so there is a lot of
inserts and updates.

autovacuum = on # enable autovacuum subprocess?
autovacuum_naptime = 60 # time between autovacuum runs, in secs
autovacuum_vacuum_threshold = 1000 # min # of tuple updates before
# vacuum
autovacuum_analyze_threshold = 500 # min # of tuple updates before
# analyze
autovacuum_vacuum_scale_factor = 0.4 # fraction of rel size before
# vacuum
autovacuum_analyze_scale_factor = 0.2 # fraction of rel size before
# analyze
autovacuum_vacuum_cost_delay = -1 # default vacuum cost delay for
# autovac, -1 means use
# vacuum_cost_delay
autovacuum_vacuum_cost_limit = -1 # default vacuum cost limit for
# autovac, -1 means use
# vacuum_cost_limit

I also uncommented this too I am not what they are though ?

vacuum_cost_delay = 0 # 0-1000 milliseconds
vacuum_cost_page_hit = 1 # 0-10000 credits
vacuum_cost_page_miss = 10 # 0-10000 credits
vacuum_cost_page_dirty = 20 # 0-10000 credits
vacuum_cost_limit = 200 # 0-10000 credits