If you are going on a business trip.. stay close to the business.
(search within China forums.. we've discussed a lot of hotels
in various different threads already)
Here is a detailed map of Beijing:
http://www.mapmatrix.com/asia/02101.pdf
this will give you a better idea about the city and help you pick a hotel
Taxi's are not expensive, and getting around is very easy.
I've stayed at Marriott Palm Spring (I think thats the name) Apartments
near chao yang park. and it was excellent.
You can always ask hotel staff for suggestions, just dont fall for their
car service/taxi gig.. just take a regular taxi... plenty around.
Just keep in mind.. Bargain a lot, what ever they ask for.. start with 1/10
of the ask price..
Some bargains ( 400RMB -> 20 RMB), ( 1200 RMB -> 2 for 80 ) you get the
idea.
All advise posted by others above is also great.