You will need a saddle to ride the spiders:
You can tame the spider with spider food or with the golden spiderfood. The golden spiderfood will works instantly and although the spider attacks you. The spider food only works if you are not the target of the spider.The spider food and the golden spiderfood heals the spider if you rightclick on it.The spider food also heals the spider if you ride it and hold it in your hand.
Craft the food:
- The tamed spider won`t disapear even if you set the difficult to peacefull.
- You can also tame cavespiders, but they are slower than the big ones.
- You can use leads on spiders.
- To saddle a tamed spider you have to press shift while clicking right (with no item in your hand)on the spider. This will open a spider inventory, where you can put the saddle in and armour too.
Craft the armour: