Sometimes the obvious is not so obvious, so that's fine. Here is what you can do:
1. To freeze the mountains : Move the timeline indicator on the frame that you want to freeze.Now, click on the freeze frame icon (an icon which looks like a camera) just above the timeline and insert those frames in the timeline. Now to put the caption, click on the 'T' icon above the timeline and you will get the Caption.
You can read more about it on : http://help.adobe.com/en_US/premiereelements/using/WS5649B74B-FD66-47eb-9D04-89F8227DD29E. html
2. To add the captions or Titles (as Premiere Elements calls it), just click on the 'T' icon and a Title will be added wherever your timeline indicator is. Also PRE provides various text animations that you can apply on the text,
You can get more details from: http://help.adobe.com/en_US/premiereelements/using/WS92577ECE-508F-4b46-AF1F-8F3E74F18B87. html
The "Crawl" Presets will give you just that, a "preset" Crawl. If you want to customize the Pan of the Title, you can do that by Keyframing the fixed Effect>Motion>Position. This will allow you to "follow," or otherwise control the horizontal motion of the Title.
This control is accessed from the Effects tab, and then through Edit Effect, with your Title Selected in the Timeline. You will see the fixed Effects (automatically added to each Clip by the program), and then twirl open the Motion Effect, where you will see Scale and Position. In your case, you would Keyframe just the Horizontal Position.
Thank you - both very useful answers. i_dream_of_jeannie's answer perfectly did what I was looking for and also played with Hunt suggestion which I'll be able to use in future videos.
I have two follow on questions:
1 - When the video rendered, on a couple of occasions I'd forgotten to delete original 'add text' caption which comes up on the screen and just added my own in various places around the screen. The video rendered. Now when I go back to the timeline, I cannot seem to select the text so as to delete it. It will let me add or delete additional text, but not text after render. Is there any way of getting rid of that or do I just delete my freeze frame section and start again!
2 - The freeze frame technique as described worked fine and I left the freeze at the default time of 5 seconds. I added caption and rendered. The only slight problem is that the text caption stays on the screen about 3/4 of a second longer than the freeze frame, so that the captions are still there for a short while the movie has started to play again and pan. Is there any way of changing the length of time the title stays on for, or should it already just be staying on for the 5 seconds to match the freeze frame? I tried 'grabbing' the timeline and pulling it to the right to slightly lengthen the freeze frame, but that also lengthens the time the captions are on by the same amount.
Any thoughts on the above greatly appreciated!
To answer your questions :
1. You shouldbe able to double click on the 'Add Text' in the Monitor and when you see a selection boundary, just delete it.
2. To make the title a little shorter, on the timeline just select the Title track, take your cursor to its end and drag it to make it shorter. Probably you can zoom in the timeline so that it will be easier to see it.
Let me know if this helped.