perldoc -f srand will tell you more about this as well.

In Perl's before 5.004 it was important to set a good srand value, but since then it's all been taken care of for you - one will be generated the first time you call rand.

If you're not doing anything more advanced than "simple randomness" for nothing particularly important (i.e. not cryptography or whatever), then this should be all you ever need.

If you're doing anything more complicated then, as others have said, look at something like Math::TrulyRandom

(Also, don't forget to check out Simon Cozens' article on How to choose a good Perl Book. I've never actually heard of the Brown book - what's it like?)

Tony