it really depends on the distribution,
redhat based distro's usually create 3 partitions on install by default,
i use mandriva linux (redhat based), on install using the default settings, it does the following partitions,
12gb for / - which is the root partition, the one where the operating system is
3 - 4gb for swap
the rest is for /home, it can be re-sized to how you want, but is not necessary,
this way of doing things is very easy when it comes to a fresh install, any distribution that uses this setup can be used to just install the operating system,
the / partition, swap and /home are already there,
for instance, i can install pclinuxos, it will install the operating system to /, over-writing my mandriva install,
swap and /home will not be touched and all my files and folders will still be accessible,
then again, i may want to install fedora, tinyme, minime, etc and the same will happen,
i can't comment on debian based systems like ubuntu and mint because i don't use them or like them,
but i do know that you have to specify and create extra partitions - just seems like to much hard work for me
so in answer to your question - use a decent version of linux and let it do it for you
seriously though - 12gb /, 3gb swap and the rest for /home (not forgetting to create your links)
oh - and just a note, on my 12gb / partition, i am using only 5gb and i have quite a lot of programs installed,
i could use less but i have 2 kernels installed, one is for everyday use and the other is needed for virtualbox,
so even 12gb is a little overkill