It's a bit of a broad question: the answer is any to all QlikView services except for the QlikView Management Service, which can only run once in the cluster.
However, if you only have one QlikView Publisher licensed, you want to stop the QlikView Distribution Service and the Directory Service Connector service. Or depending how you are doing load balancing (if you want to) you can also disable the QlikView Webserver/QlikView Settings service (if using IIS).
Said in different words: to be able to use the power of the two nodes, you need at least the QlikView Server service running on the second node. But considering your setup you may want to have other services up as well (except for the Management Service).
Mark, just to expand upon Miguel's post, in your case I would expect in the Qlik... services listed/installed on the server in question, if the admin installed more services than are actually necessary, generally folks set the ones not needed to Disabled or Manual, that may help you in the future, but to Miguel's point the key one would be the QlikView Server service from what I could tell from your post.
The other thing you can do is in the QMC, check the Status\Services area, that should list what services are configured to run on which servers, and then you just start the service related to the one that is down there. Here is acronym translation just in case:
QMS - QlikView Management Service
QDS - QlikView Distirbution Service
DSC - QlikView Directory Service Connector
QVS - QlikView Server
QVWS - QlikView Webserver or QlikView Settings server if using IIS as web server.
Hopefully this may help you in the future. If Miguel's post got you what you needed, be sure to give him credit as well by clicking the Accept as Solution button on his post and to let others know his suggestions worked.
To help users find verified answers, please do not forget to use the "Accept as Solution" button on any post(s) that helped you resolve your problem or question. I now work a compressed schedule, Tuesday, Wednesday and Thursday, so those will be the days I will reply to any follow-up posts.