The rulebook states that your character needs to make monthly payments to maintain his lifestyle, but the character creation process allows you to buy a number of months of a lifestyle. So if I buy, say, 10 months of a Low lifestyle at character creation, does that mean my lifestyle costs are covered for the first 10 months of the game? I'm pretty sure that's what the rules mean, but I'd like some confirmation.

Also, in terms of game-time, about how long do you generally keep a character going? Do characters usually last a number of years? A few months? Maybe only a few weeks? I understand that character lifespans can vary greatly due to certain circumstances (like death), but maybe you can still come up with a rough average.

Yep

Edit: My campaign has a few days of downtime between runs, at most a week.
Edit2: Which means the characters will be paying up for lifestyle next session
Edit3: (I suck at thinking before I post) It would depend entirely on the time frame of a given campaign, but I wouldn't think that you'd see many birthdays for a character

I have found no need to prepay lifestyle more than a couple months. The only exception is when you have some money to burn at chargen, and there is usually something else to spend it on. Money costs too much at chargen in SR4 to waste BPs on something you won't use for months and may never use because you shorted your character somewhere else.

During gameplay, coming up with 2000 nuyen a month should not be a major problem. If you want to stock up then, go ahead. If there are better things to spend your money on during gameplay than prepaying lifestyle, it only reinforces my point of wasting resources at chargen.

Disregarding the question about lifestyles, though, I'm still curious the average character lifespan. I know Shadowrun is supposed to be lethal, so do you find yourselves making new characters rather frequently, or do you stick with one for a good while?

(In case you haven't noticed, I'm new to Shadowrun.)

It depends on how nasty your GM is, how well "balanced" your team is, how smart you are strategically (hell no I won't do that run, it's suicide!), and how smart your team is tactically.

My current character has probably been running for about 6-10 months now in game time... and I've been playing him for about a year and a half real time.

A few things a new Shadowrun player should know:
1. Get some kind of highly portable communications device for your teams. -- Edit: IE, get a commlink and subvocal mike, preferably with an earpiece.
2. Area of effect evens the odds, so make sure you always have some available. (Grenades, stunballs, etc, etc)
3. Suppressive fire is good for stripping a whole bunch of people of their combat pool, making them easy targets for your allies. -- Edit: Not applicable to SR4.
4. Do not forget that the melee intercept rule exists. Sitting a melee specialist around a corner (or doorway) in close quarters and having them intercept everyone coming through can be very useful.
5. A force 6 spirit using confusion power wins just about every combat. -- Edit: Not quite as nasty as in SR3.
6. At least one person on your team should have skillwires.
7. If your GM is cool with it, I find that having only NPC deckers can really improve the flow of the game. (ie, GM can abstract away all of the bullsh*t that ends up having the decker play a separate game) -- Edit: Not as important in SR4.
8. If you can't take them down on the first initiative pass, then increase their target numbers. Smoke grenades (especially when you have thermographic vision and they don't), spirit confusion, tear gas, flash packs, invisibility, darkness... increasing their target numbers increases your survival rate tremendously. -- Edit: Not directly applicable to SR4. Reducing dice pool is still good stuff, though.

V, erm.

I'd say that at least 3/4 of that stuff doesn't really apply to SR4. Or at least takes a little bit of translation to make it do so.

Ah hah. Screwed up and throught I was in the SR3 forum.

In our games, we generally use real time as the timeline, witht he exception of when an adventure takes too long to wrap in one session. This helps us keep track of things like how long it takes to learn a skill (something that hasn't come out in sr4 yet.) Characters in the camaigns I've run generally have a relatively long lifetime; esp. after I made the other people start gming. When people retired their sr3 characters some of them had 200 karma.... which you don;t get in 3-4 months of play unless you're playing alot.