Dictionaries
These are a few dictionaries I find useful:
http://oxforddictionaries.com/This is an Oxford dictionary. It includes games, puzzles, tips and more...
http://dictionary.cambridge.org/
Here you will find online English dictionary and thesaurus by Cambridge.
http://www.urbandictionary.com/
This dictionary posted and defined by its reader!
http://www.slovnik.cz/
Slovník.cz is another online multilingual dictionary.
http://www.thefreedictionary.com/
This dictionary is ordered by subjects available in ten languages.
Sites For English Students
http://www.helpforenglish.cz/A very useful source of grammar and vocabulary! (Designed for Czech learners)
