Applying Service Pack 1 to SharePoint Foundation 2010

Hi,

I have SharePoint Foundation 2010 RTM environment, and right now the management want to apply the Search Server Express 2010. I found out that there are already many CU's and SP1 for both SharePoint Foundation 2010 and Search Server Express 2010.

I'm a little bit confused regarding the sequence or order of installation.

I read some article saying that for SharePoint Foundation 2010, SP1 should install first then followed with June 2011 CU