Quests
If you want to take the players off the main field to another location, then congratulations: you have a quest!
There are several types of quest, e.g.
Outdoor Quests: You go through the Sentinel Gate and the quest takes place in a field/forest location in the quest area.
Tent Quests: You go through the Sentinel Gate to and the quest takes place in an encounter tent.
HoW Encounters / Eternal Audiences: You go through the HoW portal and the quest usually takes place in an encounter test (but might also use an outdoor quest area).
PLVs / Trouble Near Anvil: You go off field to the 'CS Offices' and into an encounter tent.
Each possible quest route has its own implications:
Getting there
Sentinel Gate
If you're using a sentinel gate conjunction, you will need to set up a conjunction through the data interface. Please consult with either the encounter tent setters or the skirmish crew that are going to be helping deliver your quest before setting the number of people who can use the conjunction - the limits are usually based on how many people can fit in a set, or how many people can be given a good fight.
You will then have to drop hints to the players to get them to go and check for the conjunction - this is called 'hooking' the quest. The players will need to know the exact location so they can use Detect Magic on the Sentinel Gate to find out when your quest is and how many people they can take.
Do not hook the quest to several groups without them knowing about each other. Please strongly avoid doing anything likely to end up with several groups turning up to the gate intending to go on the quest, only to be stymied by the gate size - no-one has any fun arguing at the gate. If you have to drop your hints to several groups of people, make sure they all know about each other well in advance of the quest time so they aren't left sorting it out at the gate. People rarely have any fun with not going on quests, so ideally attempt to tailor your quest so that the number of people who hear about it and want to go is similar to the number of people your conjunction accommodates.
Make sure someone who will be at the gate at your conjunction time - e.g. an NPC, you, a skirmish ref, a field ref - knows exactly where the conjunction is going OOC and is happy to lead the players to the relevant location. Ideally, also make sure someone who will be in radio contact at the time knows this too - in case something happens to delay or incapacitate your primary source. Remember that non-Imperials can't go through the gate - so if your hook NPC is a Herald or otherwise not an Imperial citizen, you'll need someone else to escort the players on the other side of the gate. Remember that NPCs going through the gate count towards the gate number.
Make sure that you have some kind of on-field presence making sure that either the quest happens, or we know about it well in advance if it's not happening - particularly if you have a skirmish group booked. It's no fun standing around in the woods wondering if the players will show up. The on-field NPCs like egregores, CS, bards, Darren for the Raptors etc should be your first port of call for this. It's okay to hint about quests in letters in packs, but it's a really bad idea to make that your only source of information; if you do give enough information in a pack to check a conjunction, make sure your NPC presence checks with the person who received that information to avoid the 'several groups turn up at the gate' problem.
HoW Portal
If you want to use the HoW portal to get to your quest location, you will need two things: a time and an escort.
The HoW portal isn't booked, because you usually need an IC escort to use it (so it's clear where you're going even if there's a clash) - if you want to have it just open to a location without an IC escort (in which case you'll need an OC ref there to do the escort duty) then it's polite to mention that on the timetable, but this is rare enough that there are unlikely to be clashes.
The HoW portal goes to realm pockets, not to areas of the real world. A pocket can be connected to various different areas of the real world, allowing people from different areas to meet - but everyone must go back to their previous real-world location afterwards - you can't drag someone through to a different real world location, or bring anyone from a different location back to Anvil with you.
PCs never go to the Realms themselves - the realm pockets can be connected to areas of the Realms, but actually going through into the Realms is a one-way trip into death or Herald transformation (and consequent retirement, as heralds are not appropriate PCs).
If you are using the HoW portal and the Mirror is up in the HoW, please inform whoever is operating the mirror (Dave Young will probably know who) of the time and realm of your HoW portal opening, so that it can display the relevant information for the players.
You can distribute the information about the time of the HoW portal opening however you like - for limited-numbers audiences you should have an escort NPC who can check tickets or approve or disapprove of people going through. If you are running an open portal, be aware of the limits of the space you're using on the other end and try to make sure not more than the number of people who will fit will want to go through - having to close an unescorted portal against further entrants for safety reasons will probably disappoint players.