What should do the scaling -- my player, my receiver, or my TV?

[turtleboy]

I have a Sony BDP-350 Blu ray player hooked up to an Onkyo srs-606 and a Samsung 61 inch DLP TV which is 1080p. I don't remember the model number, but it's about 2 1/2 years old (pre-LED version).

Let's say I'm watching a regular DVD.

I know very little about scaling or upconverting, despite reading some FAQs on it.

What settings should I use to get the best picture on my TV?

I understand that the player can output 1080p, or it can output whatver the native resolution of the disc is. (Is this true?)

The Onkyo can upscale to 1080p, but I heard it's not very good at it.

The TV itself has its own scaler.

It's very confusing.