If you're using Bootstrap 3 you'll need to do the following. In the console:
rails g kaminari:views bootstrap
Then, replace the contents of app/views/kaminari/_pagination.html.erb with the following:
<%= paginator.render do %>
<ul class="pagination">
<%= first_page_tag unless current_page.first? %>
<%= prev_page_tag unless current_page.first? %>
<% each_page do |page| -%>
<% if page.left_outer? || page.right_outer? || page.inside_window? %>
<%= page_tag page %>
<% elsif !page.was_truncated? %>
<%= gap_tag %>
<% end %>
<% end %>
<%= next_page_tag unless current_page.last? %>
<%= last_page_tag unless current_page.last? %>
</ul>
<% end %>
Replace app/views/_first_page.html.erb with the following (note the change to the class of li and from link_to_unless to link_to):
<li <%= "class=disabled" if current_page.first? %>>
<%= link_to raw(t 'views.pagination.first'), url, :remote => remote %>
</li>
Also replace the contents of _prev_page, _last_page, and _next_page in a similar fashion (you'll just need to change "current_page.first?" to "current_page.last?"