Wanting to upgrade my dslr?
The past 2 years I have been using my pentax k-x, and I'm wanting to upgrade as I'm going to be entering into a photography course, my budget is 3000 and I'm wanting a mid-level dslr… I was think about getting the Nikon d7000… Anyone have other suggestions? TIA x
Added (1). I'm aware that an expensive camera doesn't mean great shots. Much like a certain stove doesn't make a chef good. Here is a link to some of my photos, of course, they're not the best, But I haven't had any courses, which is what I'm wanting to do, to become much better. I use a pentax k-x with the kit lens. 
You can also consider Nikon's 800 or 800E. Its new in market and have better specification.
D7000 is a good choice for a mid- to high level camera. If you want to sacrifice a few features a D90 would be a good choice plus its a few hundred cheaper. With your high budget, you could even upgrade to a D700 or D800 for just under $3000. The D700 and D800 are in nikons fx format, so the sensor will be create an incredible image. The D800 has a spectacular 36 megapixels if you ever decide to make massive canvas prints. The D800 also can create great Full HD videos. But the D700 and D800 are generally for a much more advanced photographer.use the link to help you decide. Skill wise, the D7000 is great for a mid level- high level photographer. But with your price range, you could purchase a D800.
oh, and with cameras as amazing as these, you need a good post processing software. And you can't ever go wrong with Photoshop, or Photoshop lightroom.
Nikon D7000 is decent as well.remember, no matter what high-end camera you use and you don't know the proper way of using it, its just a waste.
it's not the bullet but the shooter.
You can get one of the Canon EOS Mark cameras.
A 55-250mm zoom will cost a lot less than a new camera and probably give you the flexibility you're looking for.
Nikon aren't any better than Pentax, they just spend more on advertising.
Firstly - your photos. Apart from a couple where the white balance looks a little cool, I'd say they were a good set of portraits - lighting and exposure are good & you've capture the children's expressions well. Focus is ok too - you just need to work on composition.
You seem to be doing ok with the gear you've got!
If you really want to upgrade, then the D7000 is a good choice. But before you sink money into a new camera system, consider upgrading the lenses you use with your Pentax. It is the lens that has the greatest influence on image quality (other than the skill of the photographer) rather than the camera body.
Invest in some quality glass - for portraits, I'd recommend a 50mm f1.8, and an 85mm f1.8 or a 24-70mm f2.8.