FREE: Super Smash Bros 3DS Digital Starter Strategy Guide.

its not a printed guide. its from a one time use code for pre-ordering at walmart. you can save guides to use as you want. or you can access them from the links over and over.

even though they list these guides as 14.99 values, its my understanding they are called "Digital Starter Strategy Guides" for a reason. i dont believe they have all the chapers the full primagames guides do. more than the preview, but less than the complete guide.

http://www.primagames.com/shop

i dont know anything about the 3ds's abilities. if you can surf the web on it, you should be able to?

from the 3ds wiki, concerning the 3ds web browsing abilities:

The browser does not function as a primary app on the Nintendo 3DS system and can be used while another application is suspended in the background. The browser is mainly controlled with the stylus but can be controlled with the Circle Pad or the D-pad to cycle through links on the page. The browser supports HTML, CSS, JavaScript and some HTML5 elements but does not support Flash, video and music files.

i dont know anything about the 3ds download situation. i don't own one, this is from my niece's xmas. you're probably more familiar with what the system can and cant do, than i am.

you might try a general google search:
https://www.google.com/?q=prima+games+guides+3ds+download