If you're not familiar with the Limited format, I would suggest reading the official Limited rules first! Or you can read the TL;DR version below
Just choose the packs you want to draft, hit "Create room" and copy the URL from your browser and share it with your friends! After joining any player can change their nickname at any time if they want to.
After everyone is in the room, the creator can press "Start game" (if you are the creator of the room) to start the game. The room will be closed (no one will be able to join it after that), and everyone will recieve the cards from the first booster.
Then you can pick any of the presented cards. After you made your choice you have to wait for everyone to make their choice. You can see who already picked their card by circle indicator in the player list. If the circle is empty that means that that player haven't picked a card yet.
During the draft process, you can see all the cards you drafted in the Pool section. You can export your Pool to PonyHead at any time by pressing "Export deck" button. That will open a link in a new tab (or window, depends on your browser preferences) with a deck on PonyHead with all the cards from your pool.
After you finish the draft, just export your Pool to PonyHead and do whatever you want with it :)
The main difference between Limited and Constructed is that players do not build their deck from the cards they own, but instead from the cards that they open from booster packs.
Note: In limited format your Problem Deck should contain exactly 5 cards (instead of 10). And Draw Deck's minimum size is 30 cards (instead of 45).
There are two Limited formats: Sealed and Draft. In Sealed, each player opens 8 booster packs and builds their deck from the cards they got. Draft is a little bit more tricky than that.
In Draft each player brings 4 booster packs. Then everyone sits at the table and opens the first pack.
After the first pack was opened, each player picks one card from it and takes it. Then remaining cards are passed to the person that are sitting left to them. When everyone has picked their card and passed the remaining cards, the process repeats. Everyone picks the next card and passes the remaining ones.
When there are no cards left, everyone opens the next pack. The process described above repeats, but this time the direction of passing is changed: players should pass cards to the right instead of the left.
There is a certain list of cards that players may freely include in their Limited deck even if they didn't get those cards from packs.