When you upload a template to your blog, you have to configure page navigation properly.
For example, if you want to show 8 posts on home page first go to "Settings" --> "Formatting". (if you are using Blogger new interface go to "Settings" --> "Posts and comments")
Change "Show at most" property as 8. save the settings.
Now go to "Design" --> "Edit HTML". (if you are using Blogger new interface go to "Template" --> "Edit HTML"). click on "Expand Widget Templates". find this:
var postperpage=4;
Look at the image below:
Numbered Page Navigation
Now change the above line as,
var postperpage=8;
Save the template. now navigation will work correctly.