Custom.nsh to run a service

Hey guys i have been making PAF's for awhile but i am thinking
of some apps that require a "service" to be running...

does any body have any info, or examples of "Custom.nsh script"
that would point me in the right direction....

honestly im looking for moore than some one to say
look at NSIS site! im sure it is their but how is it scripted in
a segment for a PAF...

thanks to any one that can help...i am a visual leaner witch makes it
harder than just reading..