Hong Kong is one of my favorite cities. It is EXTREMELY easy to get around. The MRT (Subway) stations are easy to find and signage is in English and Mandarin. The buses are also easy to use. Just remember what bus numbers service your stop. They are posted at each bus stop. We have used this to get around both Kowloon and Hong Kong.
There are so many places to see and visit so you need to prioritize what you want to do and see. Don't forget about the food. It's fabulous. My advice is that you eat at local places, with plenty of customers, and stay away from the hotel food and western restaurants.
Here is a link to the Hong Kong travel bureau website. It has a lot of very good information.
I know you'll have a great time in a very fun city.
Plan Your Trip | Hong Kong Tourism Board