Business Travel to Guadalajara?

I have to go to Mexico (Guadalajara) on business I never been to Mexico can anyone offer me some travel tips!!! Things like

Do Taxi use credit cards?
Is it safe?
What not to eat?
Anything else you can think off.

Taxi's don't take credit card. It's safe as long as you use your common sense - act like you would travelling to any big city. Don't drink the water.

Guadalajara's a beautiful city, and nearby at Ajajic there is a big American/Canadian community of ex-pats.

Have Fun!

Don't drink the tap water. Don't brush your teeth with the tap water. Don't open your mouth in the shower.
Avoid street foods--tacos etc.
All the beers are safe.
The cheapest way to get around the city is by bus.
If you get some time for gift shopping go to Tlaquepaque.
And if you want to see how tequila is made, take a tequla tour.