Photoshop help

[jinky]

I don`t know if it`s because I had another bad nights sleep or what but uploading some images to a company for some test shots panicked me today. Lookig at images from  a wedding as samples I went to resize them in photoshop to 9x6.

The first one when I opened image size said 72 pixels per inch at a massive size


The 2nd I opened  was this one stating what I`d more normally expect to see - 300pi and the normal size I`d expect.


I`ve been messing around with the scale/constrain and resample buttons and canot remember how I should usually leave them - ticked or unticked.

I know if I leave them all unticked and just change to pi to 300 it then shows normal sizes but remind me someone simply when would I tick / use the other boxes. I know I should know this and indeed may have known this but can someone just give me a few lines idiot style to confirm what I am thinking / playing at just now. I managed to turn some 5mb + images into 1 when I first uploaded pics for sample prints with a new supplier requesting a specific 9x6 size and dont know how I did it.
How the initial chages in pix per -inchis happened I cannot remember but seemed to be when doing editing work in a number of different programmes.

[Oldboy]

I usually leave them all ticked and to reduce size, I either reduce pixels to 80 per inch or, type a size in the Pixel dimension width box. 

[Hinfrance]

Can't help Paul - I use OnOne resizer module or even simpler Faststone resizer. Can't afford Photoshop, although I think there is something in Elements that does this.

Useless, aren't I?

[jinky]

Panic earlier when I thought I had somehow made the images all lower resolution. Turns out it is the B&W ones and sepia images that showed this re-sizing trend. I think I used either NX2 or Photoscape for those and some peculiarity of doing that seemed to save them as 72 dpi - even though I have checked both programme outputs and they seem OK.