How important is a camera's actuation?

What does it mean? Does it mean that once it hits its limit, its rendered obsolete? I'm looking to invest in a Nikon D90. If you have any suggestions as to what to look for in a DSLR/ or which DSLR to buy, that would be greatly appreciated! I don't need anything fancy because I will only be shooting portraits and occasional scenery.

Actuation is merely how many times the shuuter has fired. There's no real "limit", They're tested to a certain number (my D200's like 150, 000). You can shoot decent portraits with a D40 (which I have done), a D80 (ditto), or a D200 (my D1x, however, left a lot to be desired).

It's not the camera that makes the image…

You don't understand. Dslr cameras by both Canon and Nikon are rated and tested to about
100, 000 shutter count. There are some at a million that have been in service for many, many years.

Obsolete? What does that mean? No well made camera ever becomes obsolete - never. As long as it's working properly it'll still produce photos - then it's not obsolete.

One thing more. The shutter will be important if you try to sell the camera… It's like mileage on a car.

Of the many decades before shutter counts were available, no one worried about this.

It is just yet another unnecessary thing to worry about when purchasing a camera.

I have a D90, and it is a fine camera, and especially if you are new to DSLRs, will last for many years before you outgrow it.

If you are worried about shutter count, consider buying a new D90. They have been discontinued, but there are still a lot of new ones that have nice discounts on them. You should be able to pick up a new one with a lens for around $1, 000 US.