Video and Podcast format?

FCP gives you the best (maybe only) tool you'll need and for you it's free.
QuickTime Pro.
It will be up to you to experiment with a few exports (one minute sample) at various codecs and compression levels until you find one that works best for your files.
"Talking head" videos do not need 30 fps (frame rate) or stereo audio tracks so a lot of file size reduction will be available to you without reducing your quality.
These file size savings reduce your bandwidth load and speed up your viewers experience. Since iWeb only uses QuickTime for playback you should stick with the .mov container. These will work on iPod's and in your Web pages.
iMovie can be used to create but do not use any of the "preset" export options (choose "Expert Settings") as they all use H.264 video codec and it requires QT version 7. Many computer OS's can't install it and on many older CPU's playback is a bit of a disappointment.
I suggest MPEG-4 Video codec and AAC audio (QuickTime 6 is all your viewers need).
Compression is an art form so trial and error are the only methods to get what "you" want.

The best QuickTime-based format in terms of size and quality is going to be to use the H.264 video codec. This will require all viewers (PC and Mac) to have QuickTime 7 installed on their computers. Most Macs will already have QT7 installed. The same can't be said for PCs, though. A lot of PCs out there still have QT6 versions installed and will need to be updated in order to be able to view H.264 encoded video.

The more compatible and more crossplatform QuickTime-based format is the MPEG-4 video codec. This does not require the latest QuickTime 7 version to be installed...any QuickTime 6 version will do. This provides better compatibility with more PC users out there (e.g. a lot of corporate systems still have not updated to QuickTime 7) at the expense of lower video quality and somewhat larger file sizes.

In my opinion, the best crossplatform video format (no QT dependency) available today is Flash video. I have read stats on how 97% of all computers (PCs and Macs together) have the Flash plugin installed. And with services like Google Video and YouTube using the Flash format, it's a sure bet that most people will be able to see your video. If you'd rather convert your movies to Flash yourself, you can do so with the help of the Flash package if you have that or you can use VisualHub which is fantastic for the price... http://www.techspansion.com/visualhub/

For straight audio podcasts, probably mp3 is the more prevalent format.

There's something even better than QTPro that Final Cut gives you:

Compressor

MPEG-4 is probably the best if you don't have Flash Pro. With Flash Pro you can Export Using QT Conversion from Final Cut as a flv file which is arguably the most compatible video format for viewing on the web.

IMHO Compressor is overkill for existing QT file formats. Unless they have the "originals" to work with.
MPEG-4 Video for backward compatibility we all seem to agree on.
Since it is iWeb the .flv (Flash Video) option requires just too many extra steps and post publishing editing.
Talking head video can be made at about 500 KB's a minute in file size. 8 Minute video = 4 MB's.
HTML code tricks to scale="tofit" would allow a 320X240 file to be played back at 480X360.
Everyone wins!

Here's an MPEG-4 video exported from Final Cut Using Compressor with the following settings filmed with a Canon XL2:

MPEG-4
320x240
12 fps
300 kbits/sec
Preserve Aspect Ratio Using Fit Within Size
Automatic Keyframes
AAC-LC (Music)
24 kbps
Mono
24 kHz
Good Quality

http://web.mac.com/theshow2/TheShowPodcast/thesage.mp4
9.1 MB

that's 300/kb per SECOND (not minute) and as you can see the quality is well... you decide.

If you plan on using Hub export from Final Cut as a Quicktime Movie (the same format/settings that you captured as) instead of MPEG-4 so as to avoid double-compression and/or conversion from MPEG-4 to flv in Hub which will make the quality of your video horrible

Although Hub seems like a good buy remember you get what you pay for. I do not have the app to confirm for myself but I can almost guarantee it uses only rudimentary methods of conversion and most likely does not support advanced conversion options such as 2-pass Variable Bit Rate encoding.

You asked for the best, to me that means quality and compatibility. For that you might have to jump through some hoops or take a hit investing in software, that's just some of the perks in using a Professional Application like Final Cut. There are far more superior Compression applications out there (Sorresion is the first that comes to mind), none of which should ever be classified as overkill for the video production enthusiast.

Weigh the balance between the effort you tend to put forth, the amount money/knowledge you plan on investing, and the end result you wish to acheive quality and compatibility-wise, and your end product will surely reflect your requirements.

For S's'n'G's here's a widescreen/high-quality version of the same video. This 4 min. video took over 5 hours to compress on my Mac Pro just to give you an idea, but as you can see/hear although the file size is almost double the quality difference is exponential!!! Save as source, open in QT/Window/Show Movie Info to see export settings. In short it's 15 fps, about 750 kb/second, H.264, AAC Stereo 44.1

http://web.mac.com/theshow2/TheShowPodcast/The%20Sage.m4v
22.54 MB

So there's the good and the bad for ya. On a PowerMac G5 I would estimate this compression to take about 10 hours for a 4 min video.

For professional quality results, you will no doubt find nirvana in -theshow-'s methods. Personally, for my own website additions, that kind of effort sort of defines the word overkill. 😉

But if you've got the goods...more power to you!

You guys rock!!!!!
I will try and let you know!!!!
I have another question on the way... Keep giving me inputs!
🙂