Just go to the menu Open/eBook, browse your memory card to the place you have stored your books and select the desired one. After loading it, the program will start the indexing process that won't take longer than half a minute to complete.
Jumping to any page:
Use the L/R (or the < > buttons) to go to the previous/next page.
Click over the tens, hundreds or thousands numbers to jump 10, 100 or 1000 page ahead.
Go to the Bookmarks menu to go to the first page, the last one, go to the bookmark or set the bookmark.
Click over any word you want to look up and the dictionary will open where this word is or, in case the word is not in the dictionary, the most similar word to the one you selected will appear. Then you can click over Up/Down buttons on the d-pad to browse the dictionary.
When you open the kReader, it will load the English Spanish dictionary from memory card. This will be the default dictionary. If you want to use any other dictionary, go to "Open/Dictionary" menu and select a new dictionary file to use.
Please keep in mind that the free dictionary provided is a very basic one, so lot of words wouldn't be on it.