I am a beginner at custom master page branding. I have converted an html page to a master page ,pretty simple. I know how to use the snippets too. But i notice that every single page i navigate to show the custom master page,and their content at the bottom page. I need to create other pages that inherit the custom master page navigation and layout. Can you show me the steps or point me to some tutorials.
within SharePoint online yes you can update the master page but try not to modify the master page unless you have no option! As SharePoint is an SaaS provider means that your going to find that you go quickly out of date and have an uphill battle updating the master page to incorporate any changes / broken objects when Microsoft releases any change which is all the time (weekly mini updates -> monthly then quarterly (large updates)) ;).
You should mostly do branding via CSS.
select the cog (top right) -> site settings -> under "look and feel" select "master page" -> click on "alternate CSS URL" -> select the third radio button to add your own css file. Save the css file within a document library like "Site Assets" . -> make sure you also select the checkbox to reset all subsites to inherit the new css.
tie this in with some custom page layouts and your all set!
from the horses mouth (msdn):
Anti-patterns (in other words, don't do these things)
Below list contains the key things not to do when it comes to branding your portal:
Override branding of Office 365 Suite Bar Customize branding for personal sites
By default implement your custom branding by using custom master pages
The SharePoint Online service is constantly improving.
Avoid customizing master pages. As mentioned above, updates to the service, may affect the structure of out of the box master pages. If you have implemented custom master page copying the contents of any out of the box master page, you will need to further monitor if this out of the box master page is not updated, and re-implement these changes in your custom master page. Otherwise, some SharePoint functionality may start behaving incorrectly, when your custom master page is in use. That's why customizing master pages leads to additional risks and maintenance costs, and it's recommended to avoid it, when possible.