Newbie wants to arrange order of songs

I am an Mp3tag absolute newbie. I have a bunch of songs that I bought from the Amazon MP3 store. Each song is by a different artist and from a different album. I want to arrange those songs in a certain order that will always be used when I play those songs on my Sansa Clip+. How do I accomplish that?

You probably have to number them. And just a reminder: this is the Mp3tag forum and not for a Sansa Clip+.
You can drag the files in the files list to a new order by pressing the Alt-Key while dragging.
Then, when you to the right order, use the numbering assistant to get an ascending sequence of numbers.
If the Sansa likes to order the files by filename you could rename the files with a leading number.
Use the converter Tag-Filename and the mask
$num(%track%,3) - %ARTIST% - %title%.

If you change the order manually in Mp3tag you should use
$num(%_counter%,3) - %ARTIST% - %title%

We do not know yet, what the player uses - the filename or the track number.
If the OP follows my post then he ends up with track numbers reflecting the file order that he created prior to using the numbering assistant. In this case TRACK and counter would lead to the same results.

Read the user manual for Clip+

Use Windows Media Player to create a playlist and then sync the playlist to the player.