I see many extra lenses on bestbuy.com sold with the Nikon D7000 I am interested in buying.
Are any worth it? Are they any good? And, since they bundle them, is the price better then buying the "extra" lens later on?
Those 'extra kits' are indeed cheaper than if you bought the camera + lenses separately, what you have to ask yourself is:
do I actually want that lens or am I just buying it because it comes in a kit?
Saving $200 on a lens you don't actually want isn't a good deal :) Weather or not said lens is 'worth it' is entirely up to you, they are all 'consumer super zooms' so image quality will be on the lower end of the spectrum (yea get what yea pay for).
Best Buy is generally selling consumer grade lenses because they sell to average consumers. The lenses are okay, because Nikon makes a good lens, but most of them won't be the best lenses because the buyers of those won't be shopping for them at Best Buy.
So, having said that, the question boils down to your skill. Anybody with enough money can buy top of the line gear, but are they able to use it? I'm not saying this to impugn your skill, but given your recent questions, you would appear to be a newcomer to SLR photography so you should take a hard look at that before making major investments in equipment such as pro-grade lenses. For the vast majority of us, it's not an expense that makes any sense, great pictures are still to be had from the "lowly" consumer glass out there. Heck, I consider myself a reasonably advanced amateur and the closest I have to pro-grade glass is a 30 year old Vivitar f/2.8 100mm macro (which is considered to be one of the best macro lenses ever made) that is entirely manual other than the aperture.
So, don't worry too much about the lenses, they'll probably do you fine until your skill increases. However, don't assume that Best Buy has the best price, there are a ton of sources for Nikon lenses and a little shopping around is going to get you a better deal much of the time. What's more important is to figure out the kind of pictures you want to take and to buy lenses that assist in that.
There's a difference between cameras with a kit lens, and camera kit accessory bundles.
The former are from the manufacturer, and generally give you a good deal on a low-end wide-normal zoom. (Sometimes, it's even cheaper to buy a camera in this form than body only!)
Camera accessory bundles are put together by camera stores, and include things like a cheap memory card, a crappy UV filter, and maybe a serviceable camera case and wobbly tripod.
These are high-margin items which serve to increase the seller's profits and are generally not a good deal at all. These are often also sold with the term "kit", probably in order to confuse people into buying them. You can tell you're shopping at a skeevy merchant when they insist you need one.