I'll tell you what I have and we can go from there (I actually wrote this before your last post...I didn't know that you wanted the Pioneer 50 inch, but here goes):
1. Pioneer 50 inch plasma
2. Denon AVR-587 receiver
3. Sony Upscaling 5-changer DVD player (not BRD)
4. Comcast HDTV+DVR cable box
5. Harmony 550 remote control (though the jury is still out on this one)
6. Klipsch 10 inch powered subwoofer
7. Speakers built-into my wall that came with my house (brand unknown)
I didn't think that I did until I actually got one. Previously I used a Sony Dreamsystem that doubles as a DVD player with home-theater all in one small box. The problem is that the way the output is calculated, it is nothing close to what is accurate and any other system (other than a dedicated receiver) does not do your speakers justice. A receiver has completely different output and circuitry and is the best way to get the true surround experience. Caution - if you buy a receiver, it won't be any good unless you invest in a powered subwoofer...what a difference it made once we hooked it up!
I'm assuming that your cable/dish box has an HDMI output. Is your question, "Do I need to hook-up one HDMI cable from my box to the receiver and then from my receiver to my TV?"
For those who don't know, BTW, DVI and HDMI are interchangeable as far as picture goes, but DVI does not carry any sound. There are cables that will take an HDMI output to a DVI input on a TV but you will only get picture that way, no sound if you are relying on speakers either built-in or hooked-up to your TV.
The answer to Mirrodie's question is, if you want to save some money, you don't need an HDMI receiver. This was shocking to me, I actually bought the above receiver, returned it, got the facts, and then went and bought the same receiver again. The fact is that yes, even though HDMI carries picture and sound digitally, your cable/dish box should have an optical output. My receiver (and if you haven't looked it up by now is the low-end Denon that retails from $250-300 and is one of the few ones that has the built-in XM option with neural for XM HD surround sound and multiple zones...I can play one thing inside the house and the speakers on my deck can play something else...the most options I found in this cheapest box...other brands with all these options retail for 50-100% more) has 2 optical inputs. One is for cable and the other one is from my DVD player. Optical is, for all intents and purposes of this discussion, digital and I was advised that there would be no appreciable difference in sound quality between optical input and HDMI input. So before you spend $$$ on an HDMI receiver, you may want to take that into consideration.
How many HDMI inputs does your TV have though? If it only has 1, you either need to get a receiver with multiple HDMI inputs and 1 output, buy an HDMI hub (I think, but you may want to get a 2nd opinion about that), or get lucky like me and buy a TV with 2 HDMI inputs. As a result, I have the cable box and the DVD player each with an optical out for the audio to the receiver and each with an HDMI cable into my TV.
A word of advice about the HDMI cables (and subwoofer wire for that matter). The 12 foot ones (not sure how long you need it...we had our plasma installed on the wall) retail for $120-150 at Best Buy and Circuit City. I bought two 12 foot cables for like $50 each at Wal-mart. They are Phillips brand and on the internet, these cables can be had for even less. I asked my installer about cable quality and his response was that it will either work or it won't; it's a digital technology so it's not like analog cables that gave better signal when heavily shielded. I've got a stunning picture with the set-up that I have. He cautioned that the Monster brand (most expensive) may give a slightly better picture, but the the average viewer, there is no appreciable difference (he had some he could sell me in the truck...I didn't take the bait but it was a good try). Oh yeah...subwoofer wire. This is an analog wire so shielding and all does make a difference. That being said, I bought a 25 foot wire for like $14 (as opposed to a 15 foot wire they showed me for $50) and my infant son still shakes up and down when he's near the sub. Makes movies a blast and even regular TV a whole different experience.
In December 1998 my Dad and I went into Circuit City and the nice people (read: greedy/pushy salespeople) sold us a DIVX player. This was a new technology at the time with the idea being that you buy a disc for $4-5 and you could watch it once. At that point, you could buy "unlimited views" for like $12 or you could toss the disc. Needless to say, that concept failed, we got a $100 rebate on our costlier player (was just a DVD player on steroids- you'd have to connect it to the phone line to buy another view or unlimited views...crazy). The lesson that I learned was not to pay premium for a new technology. Right now you can by a regular DVD player for $50-80 and an upconverting one from $80-150. Why pay $500-1500 for a BRD when, even though you can watch regular DVD's on it, there is a grossly limited number of BRD movies that are available?
I didn't find any one website useful. I made diagrams of how I ideally wanted to hook things up (same TV and cable box with different receivers/DVD players) and that's when I talked to the Best Buy guy and realized that I didn't need an HDMI receiver to get the best digital sound quality. Let us know what you're getting (or what you have) and maybe all us AV geeks can come-up with a solution for you. Reviews on the internet of each product gave subtle hints and the aggregate made my home theater installation a breeze and solidified my expectations (needless to say, the TV has exceeded my expectations...if it lasts, I'm hooked on Pioneer TV's for life!)
BTW - I knew nothing about any of this before, like, December 15...it's amazing what you can learn in a month! Good luck and let us know how we can help.
The XM option requires that you buy an additional $60 worth of hardware (includes antenna) and then subscribe to the service. I have XM in both my cars but we haven't added the receiver yet (probably will before baseball season).
The Harmony 550 remote is made by Logitech. In theory, an excellent idea as it really does replace 4 remote controls with one sleek SOB of a remote control. You go on the internet, input all your equipment, and the hook the remote control to the computer via USB and it downloads all the commands (and "activities" such as turning everything on to watch TV, or a DVD, or FM stereo, etc). And if it still is missing a button, you can hold your remote next to it and have it learn the codes! As a matter of fact, it is faster and more responsive than the Comcast remote that came with my box. It does have a few bugs though (when a specific device like cable box is picked, the voluem does not default back to the receiver unless you go back and choose to command the receiver alone) but I've been told that I can iron those out.
Edit for spelling and for adding completeness to my initial comments.
[Edited 2007-01-16 07:13:26]
You land a million planes safely, then you have one little mid-air and you never hear the end of it - Pushing Tin