Well, yeah it's the standard process. You want your model to be as accurate as possible. Especially if your modeling an inorganic form, such as a car. When it comes to organics you could play off any indescrepencies as natural flaws.
When it comes to creating your own Refs, you will probably have to draw them, and then you could scan them into your computer and polish them up. Though if your not much of an artist it can be difficult to find decent refs, especially for good character designs. Though it's not impossible to find them. You will have to credit the artist who created them. Now this is a great thing for modelers who don't have the ability or the time to create there own refs, but i like my stuff to be totally original.
Anyhow, using refs is a very good thing.. though allot of people will say "it takes a true artist to model without refs" well all i can say is don't listen.... It takes a true artist to take a 2D concept and bring it to life in the third dimension as accurately as humanly possible.... refs are just another tool in the tool box. If you choose not to use it, well that's just you one tool down on the rest of us.
Well don't let my ranting put you off.
Hope this helps.
www.stevenegan-cgi.com
"Your weapons are no match for ours! People of Mars, surrender!"
"Um, this isn't Mars. This is Earth."
"Earth? Earth-with-nuclear-weapons Earth?"
"Yes."
[long pause] "Friend!!"