Being able to properly configure your .htaccess file very useful if you work with websites. With this single file, you have the power to redirect users to different domains or pages. You can fix multiple 404 error pages, so that whey redirect to a single useful page or perhaps just your homepage.
Speaking of your 404 page, you can customize this page very easily by writing some lines in the .htaccess file.
Here I present to you 5 great resources to get you started learning all about the .htaccess file:
Redirection at moz.com - this is a fantastic post about redirecting pages. Read it and you’ll be a master at redirecting the proper way.
.htaccesseditor.com – A great tool where you can input some values into this handy tool and it will output what you need to write
Create your custom 404 page – A great post about creating your custom 404 page
Have a look at this huge collection of great custom 404 pages on Smashing Magazine
Master RegEx in combination with .htaccess to really same some time – check this post for an intro to RegEx