A walk in the woods - Dangerous mushrooms
I would like to give a quick overview of poisonous and toxic fungus, that could be very dangerous for your health or at least cause annoying gastrointestinal inconveniences.
The Amanita family members: muscaria, phalloide, verna, pantherina: could be deadly.
The Russola genus: toxic or indigestible.
Fake parasol mushroom. Similar to parasol m., but miniaturized, has an awful smell: very dangerous.
Boletus Satanas or Maleficus. Vibrant red or purple colour: poisonous.

Should you run into these 'guys'... keep away!
Here a complete list of the dangerous mushrooms: http://bit.ly/1jd5PbA
And now discover my three favorite edible mushroom types in my post Seasons change, so do tastes - Wild mushrooms