So should I bother with S9?
The only thing you need to understand about BS9 is that it takes a down-to-Earth/back-to-basics approach, which seemed like a great idea after the bombastic BS8, but then it just abandons that mantra during the 4th volume (out of 5).
Not, in my opinion, until BS10. Angel & Faith is phenomenal though.
Does it feel closer to the TV-Buffy?
Eh, slightly.
Does it properly address character relationships in a more realistic way?
Well I honestly didn't feel like S8 really did anything majorly wrong in this regard, but I suppose I would say yes?
Is there a guide for the order? After the fall-> Faith and Angel -> S8 -> S9?
Etc?
It's pretty simple.
1. Angel: After The Fall
The first four volumes (17 issues) are the "official" continuation of Angel. There's much more you can lump in there, specifically Spike: After The Fall and the 8-issue series simply titled:
Spike, but if you've never read a comic beforee don't worry about them.
2. Buffy: Season 8
40 issues. 8 volumes. 4 library editions. The first half is just as good as the TV show imo, and it's what made me a huge fan in the first place, but the back half gets a little ridiculous. I enjoyed it for what it is, but it pretty clearly has some faults.
3. Season 9
This includes Buffy (25 issues), Angel & Faith (25 issues), Willow (5), and Spike (5). These can be read by themselves, or in chronological order, as Mylie's post implies. Angel & Faith is
AMAZING but Buffy... eh not so much. In it's defense it definitely took a more barebones approach, compared to BS8, but it's still a little bland.
4. Season 10
Includes Buffy (30) and Angel & Faith (25). A&F was awful, and while Buffy got the creative team from A&FS9, I thought it ranged from 'just ok' to above average. I've only read it through once though (that was with monthly breaks inbetween issues), and it does seem to have quite the following on here.
5. Season 11
This is happening now. They're stripping it down to 12 issues per series (sans Faith) to create one big mega-arc. I think it's a great idea. We'll see what happens.
There are PLENTY of tangential reads that I would love to unload on you, but I think I'll just leave it at that.