For designing a custom home page layout, this is the task of the system administrator. S/he can set up a menu with tabs that only open if the person logging on has clearance for that aspect of the company information. The menu can include tabs for Trending Chatter topics and for analytic snapshots. The pending approval list is better left off this page.
Messages and alerts relevant to the person logged on can be pop-ups. The dashboard components are a matter for the system administrator. S/he can always decide later to add a new tab of something necessary, such as an offer of additional training, or a list of candidates under consideration for promotion.