Any recommendations on good hotels that are close to the main sightseeing areas? I can get some free nights at the Hilton. Any information on Hilton quality and location?

The Hilton seemed a long way out of the centre - near some sort of flyover. Normally, I'd say take taxis, especially as you're getting free nights. However, there never seemed to be many taxis on the streets, and those that I did come across were old (20 years) soviet era cars.

the usual advice in Prague is not to hail taxis on the street, as some drivers are unscrupulous, but to call one of the reliable radio taxi companies.

The Hilton is in the Prague 8 district according to one website I saw. Not my first choice of location, but within a half hour walk I'd say to Old Town, perhaps less. Still, for a free room in a luxury hotel, I'd certainly do it, and spend more on taxis if necessary.
Look for guest comments at www.tripadvisor.com

Hi roman,
The Hilton is indeed in Prague 8.
We recently stayed inthe Seiber which is further than the Hilton by foot.
It took us no more than 15 mins to Wenc square and the hilton is close to the Florenc metro station. Not sure about the hotel but the location is far enough away from the madding crowds but not too far out to be amongst them if you so desire.

Good luck
Muck

If you are OK with taking the metro (I love the Prague Metro), you should definitely stay at the Hilton, if you can get free nights. It is not a bad area. The Florenc stop is right there, as mentioned, and there is a huge bus terminal, also. You can always get a taxi (AAA is the best one - and they are everywhere), and you will need one after midnight, when all but the night trams cease to run.

Thanx for the notes. Most helpful.

Try the Hotel Charles in the Lesser Town. Very convenient for walking and reasonable.