My philosophy is to almost never disable services. I believe in having a very consistently configured machine with the least number of tweaks possible. That gets me, IMHO, a stable machine and no surprises at Windows Update. (I guess that means I'll never use vLite! :))
The well known tweaking guides out there are not written from a sysadmin's viewpoint.
However, you can go to Add/Remove Programs and go to Windows Features, and turn off those you don't use. I never ever use, for example, Simple TCP/IP Services, on anything. There are no doubt other examples. If you find you need the feature you can turn it back on.
Same goes for server roles; if you have SNMP installed but don't use it because you don't have a device that uses it (or the tools to use it costs too much/are bloated/make no sense) then remove it.
But I never go and disable a service just to try and make things "faster".