I haven't been to KL since 2008, but I doubt it has changed much since then. In terms of hotels, I stayed at the Traders Hotel which was great. Our room faced the Petronas Towers and bar/ pool area was great. There are plenty of big name hotels to chose from, it will just depend on your budget.
I recommend a day trip to Malacca or Melaka in Malay as there is so much history to and the architecture was great (IMO) - your hotel can give you names of tour companies etc.
In terms of food, I enjoyed Madam Kwan's at the KLCC (which is great for shopping) , check out Chinatown as well for cheap tasty meal.
Also check out the Malaysia Tourism website - that will provide you with plenty of information.