You’re looking for the right verb/phrase for:

“When you quickly look through the television guide/program schedule to watch something, you are …”

The most natural and commonly used terms are:

  • “browsing the TV guide”
  • “scanning the TV listings”
  • “flipping through the channels/guide”
  • “skimming the program schedule”

If you want a simple fill‑in:

“When you quickly look through the television guide/program schedule to watch something, you are browsing (or scanning) the TV guide.”

Quick Scoop: Language angle

When people talk about this casually today, they usually say things like:

  • “I’m just browsing the TV guide to see what’s on.”
  • “I’m scanning the channels for something to watch.”
  • “I’m flipping through the guide real quick.”

“Browse” and “scan” both suggest a quick, not-too-deep look, which fits exactly what you described.

Tiny usage breakdown

  • Browse – relaxed, open-ended, you don’t know what you want yet.
  • Scan – a bit faster and more purposeful; you’re hunting for something.
  • Flip through – emphasizes the physical action (remote, pages, on-screen grid).

All of them are correct; “browse the TV guide” is probably the most neutral and widely understood in current usage. TL;DR:
You are browsing or scanning the TV guide/TV listings when you quickly look through the schedule to find something to watch.