Yes, you can use custom master pages with SharePoint Online. Yes, it will involve work. But there is no such thing as custom branding without work. The issue is lack of control, and that is a scary thing to face.
It would not occur to most power users that web parts can also be added to a Master page, and while this behavior is not available in the SharePoint UI, it can easily be accomplished using SharePoint Designer
How to add “Hidden” metadata to your page layouts so that they are only visible when editing the page, also provides the specific field names for the most common SharePoint 2010 base columns and web controls.
Here is a simple way to add in the logged in users profile picture right before or after the users name in the SharePoint 2010 ribbon.
Using the 2007 theme engine in SharePoint 2010.
Publishing sites use master pages, page layouts, Web Parts, and cascading style sheets (.css files) to enable designers and developers to create branded websites with designs that can rival those of many current and popular websites today. This article focuses on the mechanics of properly planning and creating a design for an external, Internet-facing website with a publishing site.
The SharePoint branding experience broken down to four levels.
Extensive MSDN articles on branding and customizing SharePoint.
Very comprehensive first part of an article series focussed on stylesheets and what you can do with them in a SharePoint environment.
Update: Here are the other parts:
Intranet links for today:
- British Telecom’s internal Podcast platform, Podcast Central [Link]
- Video interview with Toby Ward on SharePoint for Intranets [Link]
- What Does Your Intranet Brand Say? Some quick facts on naming your intranet [Link]
- A short survey from ThoughtFarmer: How 2.0 is Your Intranet? [Link]
- 17 Microblogging Tools for Business: If you want Twitter on your intranet [Link]
- Some case studies from Noodle, a wiki-based social collaboration tool [Link]
- Some thoughts about intranet use on mobile devices [Link]