If you want to line your images up nicely without using the gallery you can insert a table. Bear in mind that the table WITH the images must fit within your page. You cannot use the editing window as a guide, you must preview your page to be sure it looks ok.
Make sure you have the kitchen sink open and look for the table icons on the bottom row. Hover over each icon to learn what does what.
Insert your image making sure that the alignment is set to NONE. Always use None when using a table. If you want a border, now is the time to add it using the advanced tab. If you forget and want to add a border after creation, click somewhere in the table cell that is not the image, find the table cell properties icon, click on the advanced tab and select your color. You can see that I’ve added it to two cells below.
If you want to use larger photos, use the gallery option, however this would also work with larger photos if you used one column per row.