Although, it depends a bit on your origin but still you can keep the following things in mind when coming to Bangalore:

1. Don't expect too much from the city in terms of what you might have heard about it in the past. Things are dynamic and they keep on changing in Bangalore faster than they change anywhere else.
2. As far as locality is concerned, it would be better if you choose a place which is nearer to your office. This is because, the traffic condition is worsening day by day so a lot of time is wasted during commuting. So if your office is in Electronic City, try to get a place near Silk Board. If you office happens to be on Outer Ring Road or Whitefield, try to get a place near Whitefield / Marathalli or at max HAL road. If you are going to have your workplace near Hebbal, stay there itself. Just a small observation, most of the north Indians live around Kormangala and BTM though there is absolutely no issue if you choose to live anywhere else because there is no need to worry about being alienated.
3. Also, here when you take up an apartment, you need to pay about 10 months rent in advance as security so better prepare for it.
4. Food wise, usually you will get all sorts at every place I mentioned.
5. Public Transport is very good (if you count out Auto Rickshaws of course). Buses travel to every nook and corner of the city and you can get single day or monthly passes according to your budget and frequency of travel. You can get both AC and Non AC kind buses for every place.
6. There are plenty of places to hang around, around Bangalore city if you are interested in natural beauty. In the city itself, there are lots of restaurants and pubs amongst which the better ones are in Kormangala, Indira Nagar and places around MG Road. As compared to other cities, the prices are on higher side here so prepare to shed out some money before you plan to see around.
7. Most of the places shut down after 11 PM. Even all the pubs. The buses stop plying after 10~1030 so it is better to get back home before that. Use weekends to the fullest but avoid paying hefty amount to Auto Rickshaw wallahs.
8. There is not much problem about security but better take precautionary measures which applies to everywhere anyways.
9. If you can speak Kannada, that will be an added advantage. If you don't, there is nothing to worry as almost everyone can understand English or Hindi or Hinglish at least.
10. Again, don't expect Bangalore to be a super hi-fi city which it isn't. It is though much more open-minded as compared to regular Indian cities but it still is an Indian city and there are advantages and short-comings both together. The weather here is *still* better than anywhere else so just relax and enjoy the city like people who are living here do.

Wish you a happy stay!

Updated on 18th March:
Deadline has been extended to 1 AM now on Weekends. Enjoy! (Thanks Ashish Gaur)