:welcome:
Yes, see my DIY pages.
Manuals - It depends on how much you plan to do yourself. I bought my set of 16 volumes in 2000 for $487. Those same manuals cost almost 3X that today. If you do invest in the manuals make sure you get all the latest updates (Porsche calls them "supplements"). With a new order they should give you all current supplements (about 85 to date as I recall). When supplements come out they run $9-$12 each.
A good alternative is AllDataDIY.com and they have much of the common information for a subscription price of $24.95 and $14.95 to renew or add cars.
For my 2 cents, yes. Here is why... Porsche has seen a some RMS (rear mail seal) problems on these cars and in many cases where the car has not shown signs of abuse they have replaced 5 year old engines (read "out of warranty") for free. One sure way to assure that happens (if you need it) is to use Porsche parts. Check out the Porsche Parts at Dealer cost at the top of the page.
Porsche (again) has a list of approved oils. They are listed in a TSB (Technical Service Bulletin). Porsche TSB's can be viewed online by Contributing Members - so you might want to consider that. Porsche factory fill at this time is Mobil 1 0W-40 (synthethic).
Read throught some of the posts here and in the DIY section. You will not get much HP gain with a BMC or K&N or sport exhaust. But if you add headers and re-chip/tune the engine - some folks can see 30 plus hp increases. Watch your smog laws before doing this or get a chip that can be switched.
You can view a listing of Porsche TSBs here for each model. Some are VIN specfic and some are general and some are accessory installation instructions. Contributing Members can view the actual TSB content online.
K-20 is a 17 inch wheel most 996 wheel upgrades are 18 inch. Unless those wheels have very unusal offsets the rears will not fit on a narrrow body car (996). Sounds liike they came off a wide-body car (TT, C4S, or GT2). In genereal folks that autocross tend to liket the 17's and folks that do DE's tend to like the 18's. Bottom line for theose wheels is the fronts may fit but hte rears definitely won't.
Those are good books to have although I'm not sure Bruce has updated his book with much info on the M96 engine. Check in with your local PCA (Porsche Club of America) as we have several great folks around the area for tech sessions. Besides Bruce Anderson, there are the guys at The Racers Group, RennWorks, and many more.
Well... I cringe when someone says Porsch instead of Porsche but there are certainly a bunch of folks that say it wrong. You will endear yourself to other Porsche owners (and likely be taken more seriously) by saying POR-S-CHA correctly (just IMHO).
The current model of 911 (996) drives much differently than earlier ones I grew up with. Today's 911 has lots of understeer to keep you out trouble. Certain wheel/tire/air pressure/alignment combinations can neutralize a great deal of this and make the car quite neutral handling. I would suggest attending auocrosses and driving events and talking to folks about there cars setup and then apply it to your needs and drving style.
Once again... :welcome: