How can I keep the right side bar showing on post pages

Yes, this should be pretty easy to fix.

You can compare the file “index.php”, which is the template being used by the home page, and “single.php”, which is being used by the individual post pages.

You need to make two changes to the code of the “single.php” file.

Near the top of the file, there is this line:

<div id="content" class="widecolumn">

Replace it with this:

<div id="content" class="narrowcolumn">

This will make room for the sidebar.

At the very bottom, is this line:
<?php get_footer(); ?>

Above that line, add this one:
<?php get_sidebar(); ?>

This will call the sidebar.

That should do it!

No problem!

Very simple & easy to follow instructions – worked for me first time – thanks!