"Everything is on the internet", we use to say and that's is completely true but when the time comes to search for references for a job you can Google them quickly or have a hard time getting them online. For example some time ago I was searching for a pose of an archer, there are thousands online but one where you can see the back of the archer surprisingly just a few and if you want to study the muscles on the shoulders and back, they are even more difficult to find.
So I don't rely only on internet and always use real life references and books. The first ones not always works, it's not that easy to find a dragon out there -or even a lizard at least in Canada- but from time to time I have to draw buildings, trees, public transportation and it's a good thing to go outside and take some real life sketches.
The other resource is books and here are a few I have in my book shelf and would like to share with you.

Virtual Pose Children and Teens by Mario Henri Chakkour:
The Virtual Pose series is very resourceful. They don't have too many poses in the book and that's a bad thing but the images in the companion disc are Hi-Res and full rotational so you can see the models from different angles.

Facial Expressions, Babies to Teens by Mark Simon:
This one doesn't have a companion disc and the images inside are BW so no way to do any color study here but the book includes LOTS of poses and a great variety of ethnicity, features and ages.

Comic Artist's Photo Reference by Buddy Scalera:
As the title indicates this series was made with the comic artist in mind so most are real life and fantastical action poses. The companion disc is full of good materials and many poses but the resolution of the images is not very good so it can be useful in general poses but not if you want to draw details of hands, feet, etc.

Eyewitness Books series published by Dorling Kindersley:
These are among my favorite books ever. The way they present each topic, the abundance of details and photos is magnificent. Every photo is accompanied by a description so that will give an extra insight on the topic you are illustrating. I dream I could have the complete collection. I have a few of their Spanish editions by Altea Visual as well.

The Art of Animal Drawing by Ken Hultgren:
I found this little gem online. A very simple BW book but solid in structure and animal poses. Very helpful.

The Complete Costume History by Auguste Racinet:
That's the monster of my book shelf. For a long time I was searching for a compendium of costumes from different times in History. I found this one online at a very good price and when I received it I was surprised by it's bulky size which is good to admire the reproductions on a big format but is not a handy book to carry around. It also includes the patterns for many of the costumes! So if you are into sewing that could be helpful too. In my case the patterns are useful to have a better idea of the real shape of a dress before I draw it.

Color and Light by James Gurney:
Gurney is not only a magnificent artist and illustrator, he is also a great teacher and that shows in this book. Every chapter covers different principles of color, light and composition. Whenever I'm not sure how to illuminate a scene I take a look at this book. It is also an enjoyable gallery of Gurney's paintings and illustrations.

D'Artiste series by Ballistic Publishing:
I have two of them, Matte Painting and Concept Art. This series include not only a great selection of images in the topic of each book, but also interviews and tutorials of the invited artists. Great tool. Also from Ballistic is EXPOSE, a great selection of CG artists published once a year.

The Art of…
Every time there are more and more books about the creation process of the more spectacular films in the industry. I found The Crafting of Narnia in a second hand book store. I have to admit I'm not a big fan of the Narnia films and started flipping through its pages without much enthusiasm but then I was blown away but the excellent work of the guys at Weta Workshop for the films. It has proved a great source of inspiration for me.
And then The Art of Brave which I bought as soon as I saw the movie and where I had the pleasure to discover Carter Goodrich, a great master of Illustration and Concept Art for film.

And finally the SPECTRUM books published once a year by Cathy and Arnie Fenner with the most incredible selection of Sci-Fi and Fantasy illustrators in every artistic medium, form oils, to digital to sculpture.

So here are a few of them. I hope the information was helpful. Have a nice day!

Note: For the archer I mentioned at the beginning I ended up having a professional model been taken some photos in a studio. I hope I can finish that piece soon and publish it here.