Unfortunately, you cannot display your Google Calendar as an embedded
calendar in your blog. The functionality that this depends on would open
up the blog site to all kinds of potential security problems. What you
can do is put up a link to your calendar. I found two ways to do this.
One by making a link, and one by using the RSS widget. The RSS one is a
little funny. WordPress doesn’t seem to understand the dates well,
probably because the feed from Google was not intended as an RSS feed (I guess). So it displays the date December 31, 1969 on every item if you
have ‘display date’ turned on. I found that the best way to display it is
to turn off all the details. That way you get a link to your calendar,
and a number of calendar items you specify, each of which is a
link to that calendar item. It also seems to take a long time to update,
and at first the items that showed up were the oldest ones.
You can see what I’ve done on this blog.
The other thing I did was to just create a link to the calendar. I
created a new category for it, creatively named Calendar.
To do one of these options, go to your Google Calendar, and click on
Settings under your calendar. Then click on the name of your calendar
that you want to share. At the bottom of the page, there are three links
to your public calendar (don’t use the private links for this, as Google
warns you). 
Back in your blog, go into Site Admin. To do the RSS method, click on
Design, and then Widgets. Down the list on the left, click on the word
Add to the right of the word RSS. this will cause an RSS item to appear
in the area on the right. Click on the word Edit on that new item. This
causes a little box to open. 
you can give it a name, which is what will appear on your blog page.
Then you can set the number of items that will appear, and as I
recommend, remove the checks from the boxes where it specifies to
display content, author and date. You can play around with it and see
how you like it. When you’ve made all your adjustments, click on Change
in the little box, and then click on Save Changes.
To do the link, go to Manage, then click on Link Categories. This is to
set up a new category, so if you don’t need that you can skip it. If you
do want to add a new category, enter the name of the category you want
in the Category name field, and then click on Add Category at the
bottom. Next, click on Links. Click on add new. Then type in the words
you want to appear on your blog in the Name field, and the HTML URL into
the Web Address field. 
the appropriate category in the Categories section at the bottom. When
you’re done, click on Save on the right-hand side.
