Getting to the ground
There are three stations reasonably close to the ground. The nearest is Wembley Stadium, but it is only served by mainline trains from Marylebone. Better therefore is Wembley Park, which you can reach direct from kings Cross on the Metropolitan line. The journey time is around 20 minutes, and it'll cost you 2.80 each way off-peak, or 3.90 peak (until 1900), with an Oyster or contactless card. The cash price is 5.90 each way, or a One Day Travelcard is 12.70. It's a 10-12 minute walk from Wembley Park to the turnstiles, and then it's anyone's guess how long it will take to get in.

There's absolutely no street parking within a mile and a half of the ground. It'll cost you an astronomical 40 quid to park in the official car park, which I guess is their way of saying that they really, really don't want people to arrive by car. Your best bet if you are driving down is to park some distance away and jump on the tube..
All the pubs around the ground are strictly home fans only, with the exception of the Green Man, which is officially designated as an away fans pub. They do reasonably priced food, and serve cask ale on match days, but it goes without saying that it'll get chocka. I'd therefore suggest you drink around Kings Cross, or near to where you park, and catch the tube late on.

For more info on getting there, pubs, etc check out:
Wembley area map
Kings Cross pub map
Football Ground Guide
Away fans guide
London Transport
Official Spurs site
Top Spurs (unofficial site)