I'll edit in additions from people in this discussion as well.
So, here are a few that I REALLY recommend:
-Start with a Master Key!
-Get Astora's sword and the shield next to it from the purple drake in Valley of the Drakes, opened with the master key as SOON as you get to the shrine. It's 80/0/0/80 damage and scales on str, dex, and faith. The shield has 100% physical reduc and some flame resist.
-Get a bow and 50ish arrows and shoot the red dragon's tail from under the bridge to get the Drake's Sword, a 200/0/0/0 sword with 16 str req. Good starting sword as well. Takes about 30 shots.
-Curl up in a ball in the crow's nest to be teleported between the asylum and the shrine.
-There's an easy to reach blacksmith in Londo Ruins by the water, close to the archways.
-Always use your boots of steel to protect against the lava!
-The cemetary by the shrine has a winged spear guarded by a giant skeleton. Grab the spear and run like the wind!
-Joining the Covenant of the White at the shrine is rumored to make it easier to join games of other Covenant of the White players somehow.
-Demon's Great Hammer can be gained by killing the Asylum Demon during your first encounter with him.
-Orange Soapstone is used to write messages. 100 souls each from a vendor.
-White Soapstone is used to join as a white phantom
-Souls AND humanity are lost when you die.
-From said the most important gift is the pendant. EDIT: And they trolled us! This is a lie.
-Give the Fire Keeper's Soul to the woman at Firelink Shrine to increase your Estus Flask healing amount. Rumored up to +7.
Due to several contacts we've received from users confused as to how the summoning feature works in game, we have provided this list to help.
Conditions for summoning (White Sign Soapstone):
The host (person who's game world will be used) must be human. The client (person joining the game) can either be human or undead.
The client's level must fall within 10% (above or below) of the host's level. Generally, this example formula should give you a good idea on whether you will be able to join: (LC x 1.1) ≥ LH ≥ (LC x 0.9), where is LC the level of the client and LH is the level of the host. For example, if the level of the host is 20, then they will only be able to summon players who are levels 18 to 22.
The area boss (Taurus Demon, Bell Gargoyles, Moonlight Butterfly, etc...) in the host's world must still be alive. A client can still be summoned even if the client has already defeated their own area boss.
The host must not have placed down a summoning sign. Summoning signs from other players will not appear in a host's world if the host also has placed a summoning sign down. This is to prevent a network conflict of the host joining someone else's game world while the clients are trying to join the host's game world.
After successfully summoning, the client will return to their world if the area boss is defeated, the client is killed or the host is killed.
Also, please note that there are several different servers/lobbies that are being used for Dark Souls, so you may not be able to summon a specific friend into your game even if you adhere to the steps above. We can only recommend that you follow the steps above for the best chance at being able to join a specific friends' game.