Hi!
Welcome to the forums!
The answer to your questions will vary from person to person - each individual has their own preference for how to handle what you're looking to do. For example, storing the video at native dv will result in fairly large files depending on length, many people would prefer to convert it to a container supporting a higher amount of compression like a .mov H.264, etc.
- What hard drive should I buy?
This is personal preference. Most wifi routers that actually support having a hard drive hooked to it that is not internal will look for a usb hard drive, so any external USB hard drive would be ok (as long as it's not a unit that requires 2 USB ports, one for power and one for data as not all wifi routers that support an attached hard drive can supply enough power for one). Another option would be if the router has ethernet ports on it (aside from its uplink/internet/wan port) is to get a NAS of some sort. A third option would be a hard drive in a chassis that has built in wifi, so it would act as a wifi client on the network (ie: it would look like a computer to the wifi router).
Basically you can get just about anything you want, it will all depend on the wifi router you are using.
In terms of size, my personal feeling is to get as much storage as you can afford, if you can get a device that supports multiple drives that will create a raid array (either mirroring or raid 5, etc.) that will help protect the data should a drive fail which is convenient 'cause it would suck to have to replace all that data should you use a single hard drive and it fail.
Fast hard drive,
lots of storage
raid if possible for redundancy and data protection should a single drive fail.
NAS/wifi/usb drive/shared from other system on your network is personal preference.
- What kind out wifi router is necessary?
Honestly, any wifi router will work depending on how you handle storage (preferably a N router, but a G could work if you compress the footage down and don't plan on having too many simultaneous streams, but honestly, if you're going to do this, N will give you a greater potential for higher bandwidth. You may need to make sure your laptops (unless really new) have an N wifi adapter to take advantage of N speeds). For example - if you get a wireless hard drive then it should be able to act as a client to any Wifi router/AP. If you get a wired NAS device, you will need a router that has ethernet ports on the lan side. If you want to get a USB external hard drive/chassis, then you need a wifi router that has USB ports on it for hooking in a hard drive (several manufacturers have models that can do this). There's also another option is that if you have a computer on all the time, you can just share folders containing the files from there.
- Can I digitise at full resolution or must it be compressed?
I think you've got a little bit confused here - whether you change the container and compression won't necessarily change its resolution. The resolution of a video is it's X x Y dimensions, where as the compression can affect quality. You can use native resolution at max DV quality, but the files will be fairly large, and really you can use a codec that will compress it down pretty far in terms of file size yet not greatly reduce image quality (especially when viewing on a TV). Of course finding the "just right" settings for the compression may take a little practice until you determine what you like the most.
- What software do I use to digitise?
iMovie will digitize footage. It should digitize into a .mov container, from there you can either probably use the file as is, or use a tool like Mpegstreamclip to convert the file into a different container/compression format and reduce the overall size of the file.
- What software do I use to stream?
This is easy - you really don't need special software to "stream" within your house, the shared folder, once mounted/mapped on a given mac will show the files - then the person watching can just double click on the file and begin to watch them.
If you have a system hooked up to your TV, you may need to link to the shared folder within Front Row or Plex (I personally use Plex) to navigate through your files to then play them.
This doesn't need to cost a lot of money.
I'll give you an idea of my setup; this setup may not be ideal for you, but it works for my network needs.
ok:
Computers:
Mac Pro 10.6.2
Mac Mini running Plex on 10.6.1
Vista 64 Ultimate desktop
Macbook Unibody 10.6.2
Vista 64 Premium laptop
Network:
(for purposes of simplicity, I'm going to leave out discussing switches, additional routers or other gear I use)
Mac Pro, Vista Desktop on wired network to central router (I have a separate router from my wifi, it's a long story, but it's partially due to the type of net connection I have).
DLink Draft N wifi w/ limited bridging capability connected to central router
Droboshare NAS hooked into central router
The droboshare is a 1.5 TB share (allocated so I can dynamically add storage to it up to 8TB) that holds all of my video and much of our audio files.
The Dlink acts as my primary wifi AP, and as a bridge to my tv room which is where the mac mini is.
The droboshare has a single shared folder on it called "drobo" (clever, eh?). Each computer that will want to view video, or listen to audio maps that share.
On my Mac Pro, and my laptop, it appears as a HD on my desktop, I just open it and find the video I want to play and play it.
On my Mac mini running plex, plex has an entry to the video folder in the share, I can navigate that video folder, select the appropriate file, and play it.
On the vista machines, they map to a drive letter the drobo share and play the video thru media player, media center or other video/audio app.
I frequently view 720p video stored on my drobo on the mac mini running plex - this is across the wifi - to watch it on my big screen tv.
I have an older drobo and its performance isn't the greatest, but I can still usually watch 2-4 simultaneous videos out of it before it gets too sluggish (depending on the video file, etc.)
Hopefully some of this has helped, I'm sure some is confusing, but it may at least give you a starting point.