While the city is located in western Ukraine it appears that people in Khmelnytskyi don't speak Ukrainian exclusively (as is generally the case in the nearby city of Ternopil). Not so many in Khmelnytskyi speak Russian, and lot of young people understand English.
There are frequent trains from Kyiv to Khmelnytskyi, keep alert because Khmelnytskyi isn't the final destination but rather one stop along the way and you don't want to end up in Ternopil or Lviv by accident. However the carriage attendant should inform you (in Russian or Ukrainian) when the train is approaching your stop. A good idea is to know your time of arrival and set your phones alarm 30 minutes beforehand.
Khmelnytskyi train station is rather drab and depressing as can often be the case with train stations in eastern Europe and as with bus and train stations worldwide they can often attract people of a dubious nature especially if you arrive at night so best to get away into the city once you arrive, taxis wait just outside the exit. It is also possible to get to Khmelnytskyi by bus from Kyiv (near 100 UAH).
Taxis are as with every other Ukrainian city widely available, a trip within the city should cost no more than 20UAH but if you are a foreigner you may, as with many other cities in the world, be taken the "scenic route", even if this does happen it may cost an extra 10UAH so not too unreasonable all the same. However not being a tourist destination it is unlikely that this will happen yet it might. Just make sure the meter is running.
The city centre is relatively compact and can be easily explored on foot. If you want a tourist city with a multitude of attractions then Khmelnytskyi isn't for you, if you want an authentic Ukrainian city with generally friendly people, good prices and fewer rip offs than in the usual tourist centres then Khmelnytskyi is a good spot.
Dental tourism. Ukraine is increasingly becoming a destination for dental tourism, specifically Kiev, but people may also be interested in dental treatments in Khmelnytskyi as the prices when compared to western Europe, North America and elsewhere are extremely reasonable, prices are also cheaper than in Kiev itself. An example being endodontic treatments (specifically root canal treatment) which in dental clinics in Khmelnytskyi can be completed for roughly €35 upwards (this price is for a molar tooth, pre-molars are even cheaper) This includes anesthesia, x-ray(s), the procedure itself along with the use of "gutta percha" and of course a composite filling. Crowns cost from €25 upwards for metal crowns which are ideal for molars especially upper molars (again this price is all inclusive) Full mouth teeth cleaning is €15. All prices are correct as of October 2013.
One such dental clinic this writer can recommend from personal experience is almost directly across from Hotel Centralny on Gagarina Street, the name of this surgery is unknown but a cursory look and someone will find it. Tel: +380 382650901.
Another option is almost directly across from a city bus station (it is unknown whether this is the main bus station), rather uniquely it is called "Dental Surgery" at 6, Soborna Street. Tel: +380 382651660. Unlike the above clinic here two dentists operate at the same time using the same room so don't be surprised to see another patient also having work done alongside you.
No English is spoken at the clinic on Soborna Street and only a few words at the clinic on Gagarina Street so you may need to have a Ukrainian friend or interpreter accompany you unless you speak some Ukrainian or Russian or else you will need to put your faith in hand gestures and a phrasebook. Prices mentioned above refer to the surgery on Gagarina Street, the prices at the surgery on Soborna Street are a little higher.
There is a large newly built shopping centre with a well stocked western style supermarket at the edge of the city. A taxi to it from the city centre should cost roughly 10UAH/15UAH.
In the basement of Hotel Central (Hotel Centralny) there is an eatery open to guests and non-guests alike offering nice, simple food at very good prices. There are numerous restaurants throughout the city.
Also next to Hotel Eneida although not connected with the hotel there is an eatery with nice food at excellent prices, it is located in a basement, easy to find with a little bit of looking.
There are a number of cafes, bars and nightclubs in the city. If you are a foreigner people may wonder what you are doing in their city (as it is not a tourist city) and may view you with some amusement. Keep an eye on what you drink and how much you drink, it's quite possible the locals are used to drinking more than you are! In a bar/pub a vodka (Ukrainian brand but just as good as any imported brand) should cost a maximum of 10UAH, most likely this price is for 100ml. Prices tend to be a little higher in nightclubs but not excessively. It should also be possible to buy a bottle of vodka in a nightclub, either .5lt or .7lt, for a reasonable price, under 100UAH. One nice pub which is about a ten minute walk from the city centre is "Art Pub - High Hopes" 
Hotel Centralny  (Hotel Central) at 5, Gagarin Street (near the centre) Tel: +380 382657759. Very minimal English, if any. This tourist class hotel offers the best priced hotel rooms in the city. Prices direct from the hotel start at 170UAH, as of 2014, for a passable en-suite single room with tv (no English language stations but possibly some music stations) with breakfast (you'll be given a voucher for breakfast which can be had in the basement eatery) The en-suite isn't exactly to western standards (old shower but with hot water, possibly leaking pipe from sink, no sink stopper, dim lighting) Double rooms which are roughly double the price may be a little better. Apparently the hotel has free wifi but it's unknown whether this is simply in the lobby or also in the rooms.
Hotel Eneida  is another reasonable option with similar prices to Hotel Centralny starting at about 175UAH per night, as of 2013, without breakfast, the hotel supposedly has wifi. The hotel is located a little closer to the centre being about a 5 or 10 minute walk, it's also about a 5 or 10 minute walk from Hotel Centralny. Rooms come with balconies and the basic rooms are somewhat better than the basic rooms at Hotel Centralny. Reception staff generally don't speak English but you may come across one who does.
An alternative for internet should the free internet at any hotel not work or should no internet be available is a mobile broadband dongle which you attach to your netbook/laptop can be purchased from MTS (a mobile/cell phone provider with stores all over Ukraine including 10 stores in Khmelnytskyi) for 399UAH and when topped up by 8UAH it gives unlimited broadband access for 24 hours. MTS has national coverage so the dongle will provide you with internet all over Ukraine and not just in Khmelnytskyi of course. If you already have a dongle from your home country this most likely will not work with an MTS SIM card but there is a chance it would, you could try before forking out 399UAH. The basic mobile broadband SIM pack on its own costs 60UAH with preloaded credit of 20UAH (prices as of Dec. 2011)That said, your connection could be very slow.
Ternopil The Ukrainian speaking city of Ternopil is about a 2 hour train journey away and would make a nice day trip, a return trip could be done in a day.