Once you join this side you'll never go back..
For finding stuff..
http://filesharingtalk.com/
http://www.newzbin.com/
http://www.binsearch.info/
Those are the only 'sites' I use to find stuff..
I am a header whore.. That by far is the best way to find those gems that don't make it to an indexed site.
Learn which groups have what....
a.b. = alt.binaries.*
a.b.boneless the bone yard.. its probably the biggest group out there..
a.b.mutlimedia
a.b.tv
a.b.dvd (there are a few worth looking at like that)
a.b.sounds.mp3.complete_cd
a.b.e-book.technical
that's just a few that I often check out..
#altbin of efnet has a way of searching and requesting material. Just because you can't find it, doesn't mean that it can't get added.. And quickly I might add..
Basically you can sift through headers and find what you want, or use an indexing site and find stuff that other people are looking at.. You can kind of think of indexing sites, this one newzbin whatever as sort of like digg.com.. It's a social thing, so it takes someones effort to look at those headers and find the files to post here.. Sometimes we are lucky enough to have whoever uploaded the content to post a .nzb for it right away, other times you'll have to just find it for yourself.
Clients... Well I have no idea what to use on windows.. I'm a linux fan, so I use Pan, Icedove (thunderbird) and SABnzbd. Not one fits the bill for a specific task.. Each has it's own job.
Servers... Decide on what RETENTION you need.. that's all that it really comes down to. Retention is how long the material will live on the servers.. old stuff is dropped making space for new stuff. Giganews has 240 days or so.. That cool and all but I don't really need that much retention, and once you've been using newsgroups for a while no one should really.. You'll be after 'new' content most of the time and if it's new and hot, it is posted many many times by a lot of different people. You might even be able to find the same DVD in 3 or 4 groups.. So 240 is overkill in my book.. Astraweb is having some promotion going on (maybe check) for ~ 120 days or close to it for $11USD for unlimited BW. I wouldn't pass that offer up.