Basel sits in the north west corner of Switzerland, and the town actually shares borders with both France and Germany.
The river Rhine flows through the town and divides it in two - the south and west bank of the river is known as Grossbasel (or Greater Basel), which includes the old medieval town centre. Kleinbasel (or Little Basel) sits on the north/east banks of the river, and is more modern, and features more bars/nightlife than the old town.
As for language, the locals speak a variant of German, although being so close to France you'll find that a lot of people will understand some French, too.
Main Tourist Sights
Most of Basel's sights are located in the old town, and are all easily reachable on foot. The Basel Munster, or cathedral, is located just off the main square, Marktplatz. Built between 1019 and 1500 it's a striking piece of architecture, and you can pay a small fee to climb the tower for some excellent views over the town.
Marktplatz still holds markets 6 days a week, selling fresh food and flowers, but is at its busiest on a Saturday morning rather than through the week. The Rathaus (town hall) is also located on the Marktplatz, and guided tours are available. If you don't fancy paying, then you're still allowed to have a wander round its courtyard for free.
Some of the gates to the old medieval city still remain - constructed after the earthquake of 1356 you can find the old fortifications at Spalentor (take the no.3 tram Barfüsserplatz in the towards Burgfelden Grenze), at St. Alban Tor, near Aeschenplatz (by taking the no.3 tram towards Birsfelden), or at St. Johanns Tor, near the Rhine, by taking the no.11 tram towards St. Louis Grenze.
Of course you'll have to take a walk along the Rhine, too.
Other Things to Do
If you're into your art, then Basel has the museums for you. In the city centre you can visit the Kunstmuseum Basel (found at St. Alban-Graben 16), which features a large permanent collection of Picasso, as well as renaissance art from the likes of Holbein.
If you prefer your contemporary art, head to the Museum für Gegenwartskunst (St. Alban-Rheinweg 60) around ten minutes walk from the main museum.
The Antikenmuseum Basel, across the road from the Kunstmuseum, houses a large collection of Egyptian and Greek art and antiquities. Or, for big kids, you could try the Puppenhausmuseum Basel, which is full of teddy bears, doll houses and other related items. Get along to Steinenvorstadt 1, at Barfüsserplatz, to find out more.
Basel Zoo is also reasonably centrally located, and is the second largest in Switzerland. Monkeys, elephants and all that, can be found at Binningerstrasse 40.
Getting Around Generally
Getting around town, if not on foot, is best done using the city's cheap public transport network of trams and buses. Daily tickets can be bought for around 8CHF (about a fiver) and you can hop on and off as you please.
Swiss ticket inspectors police the public transport network, and there is a zero tolerance policy on those without tickets - we'd advise you not to risk it, because there are hefty fines if you are found bunking on the tram. You'll be marched to the nearest cashpoint, or possibly police station, and forced to cough up 100CHF.
The tram is definitely the best way to the ground, and we're told that there'll likely be extra trams laid on for the match.