If I hook my unsung, do I draw 2 first or look at top 5?

When you use Baited Hook to kill your Unsung Hero, you look at the top 5 cards of your deck before the Unsung Hero's Deathknell ability resolves.

The sequence of events is as follows:

1. Baited Hook begins resolving. Its first instruction is to "Kill a friendly unit."
2. When the Unsung Hero is killed, its Deathknell ability triggers and is added to the chain as a pending item.
3. Because you are currently resolving the Baited Hook spell, you must complete all of its instructions before the chain can process any pending triggers.
4. You proceed to the next instruction on Baited Hook: "Look at the top 5 cards of your Main Deck."
5. After Baited Hook finishes all its instructions and is placed in the trash, the Deathknell trigger resolves.

Summary: You look at the top 5 cards first as part of the Baited Hook resolution. The Deathknell effect resolves afterward.

Note: I could not fully verify this ruling against the retrieved rules.