You split the video clip and then insert the photos in the split. Then you add the music to the Soundtrack track.
These are pretty basic moves, maggie. And you'll find most of them explained in my free 8 part Basic Training tutorials at Premiere Elements support sit Muvipix.com.
To "split" your Clip, there are several ways to accomplish this. Let's take but one of those ways, and explore it. Note: I'd bet that Steve covers all of those ways, in his great Basic Training Series.
Move the CTI (Current Time Indicator w/ the red Edit Line - also called the Playhead) to the point, where you wish to make the Cut. Select the Razor/Scissors Tool, and place the Cursor at that spot on the Clip. Click, and you will have Cut the Clip into two pieces.
Now, drag your Still Images (make sure to Scale them to the pixel x pixel dimensions of your Project's Frame Size, before you Import them into PrE) to the point that you Cut, and the second half of the Clip should Ripple (move to the right), to accommodate those Stills. The Video is done.
Drag the music (MP3 can be problematic, but a PCM WAV file @ 48KHz 16-bit would be great) to either the fixed Soundtrack, or to an empty Audio Track, and position beneath the Still Images. You might want to add Audio Dissolves to that music Clip, if you have not already edited it for a lead-in, lead-out.
That pretty much takes care of what you wish to do.
PS - the other two ways to accomplish what you want is to:
- Position the CTI, as desired, and hit Ctrl+K to Cut the Clip
- Before you drag that Clip to the Timeline, Dbl-click it in the Project Panel to open it in the Source Monitor. Then navigate to the point, where you want the first part to end, and set an Out Point. Drag that to the Timeline, but do not close the Source Monitor yet. Now, change that Out Point to an In Point, effectively starting a second instance of that Clip, where the first instance ended, and set the Out Point to the end of the Clip, or whereever you want that second instance to end. Drag THAT instance to the Timeline, behind the Still Images.