Is there a rule of thumb for the directions of the accents?
By now I know more or less when a word has an accent and where to place it, but i still have a hard time remembering if it is an accent grave ( points to the right: ` ) or an accent acute ( points to the left: ´ ).
Does somebody know a rule of thumb we can apply to get them right or is this something that should be memorized?
I am not an expert on this subject, but I think there is no rule of thumb for all occasions. Generally, when you have an "e", if it is pronounced with the biggest opening, like the "e" in "men", it often (but not always) take an "`". If it is pronounced with mid opening, like the "e" in "hey", it takes an "´". When the "e" is pronounced with the minimum opening (more or less like an schwa sound) or not pronounced at all ( called "e caduc"), it never takes accents. I do not know about the accents in the other vowels. As far as I know, they do not affect the pronunciation too much. I think they had phonetic value when they started being used (many centuries ago), but French pronunciation evolved and now they are just "fossil accents".
Thanks for your answers. Searching Online i also found the following article on accents: http://french.about.com/od/pronunciation/a/accents.htm , regarding accent grave and the accent acute it states that:
The accent grave: ` (grave accent) can be found on an A, E, or U. On the A and U, it usually serves to distinguish between words that would otherwise be homographs; e.g., ou (or) vs où (where).
The accent aigu: ´ (acute accent) can only be on an E. At the beginning of a word, it often indicates that an S used to follow that vowel, e.g., étudiant (student).
So basically if the accent falls in any vowel other than E it's always an accent grave ( ` ), if it falls on E it depends , like Rafaelh stated, on how it is pronounced.