Suggestions for an upgrade to a mountain bike?

I have a Claud Butler Pagan d2 and it's specs are:

Frame: 6061 series disc specific alloy frame with oversize gusseted down tube, snake stays and oversize headtube, CNC disc drop outs, round top tube and square to rectangular downtube for more efficient power transfer.
Fork: Suntour SF-XCT disc specific, with preload adjustment with 75mm travel.
Gears: Shimano TX30 21 speed with STI shifters.
Cranks: Suntour XCCT208 guarded chainset 28/38/48T. With durable cartridge bottom bracket.
Wheels: Weinmann ZAC2000 double wall rims with CNC braking surface. Equipped with 32 hole black alloy quick release disc hubs. Kenda Koyote 26X1.95 Off road.
Brakes: Quad QMD-5 mechanical disc System on 160mm pulse rotor.
Steering: Oversize 鈥渁headset鈥?with alloy ahead stem and a riser bar

I would like to upgrade parts of this bike a bit at a time but not sure what the next step up is!

Any suggestions would be great :)

Pretty decent bike there. I wouldn't be changing too much.

Obvious choices would be:
1. Tires that work on the terrain you ride on. If you like what you got leave them alone. Otherwise go to your local bike shop and get their input.

2. The fork should be replaced if you are going off road. Suntour makes good components, but forks aren't there specialty. Try Rock Shox, Manitou, Fox, or Marzocchi. These are the fork companies that have been around awhile and for a reason.

3. A suspension seat post. They can take the edge of sudden bumps and at a very reasonable cost. I've run one for years with nothing special done to it at all.

4. Lance Armstrong will tell you: It's not about the bike. That's true. Basically ride this bike until something becomes obvious that it needs to be changed. Most of all, have fun!

Hmm.. well i have upgraded parts many a time
But these parts, do actually sound good!
If i were you, i wouldn't change all of them, i shall list the ones i would upgrade,
Forks : RoxShox(any, all of them are far better) with 90 mm travel.
Cranks : Shimano with guarded chainset. Leave bottom bracket as it is.
Brakes : Shimano V-Brakes

It is tricky, you need to talk to a bike dealer for a more specified talk.
But i have given the companies i would use for the parts.
Hope i helped a tiny a bit!

Sounds like you're pretty much all set....

I'd say maybe get a few different types of tires for
different conditions- pavement, mud, sand, etc.

I wouldn't worry too much about the componentry, like
they say- it's 10% bike........and 90% RIDER!!

You are good to go as it is. One thing I would do Is get Rockshox forks.

make it loook cool