4e is modeled on approximately 10 encounters/level. So if you are playing 2 encounters/session then you will level approximately once every 2.5 months.
The experience point numbers in the game are built
so that characters complete eight to ten encounters
for every level they gain. In practice, that’s six to eight
encounters, one major quest, and one minor quest per
character in the party. (DMG 121)
That means that yes it will take you a bit over 2 years to get to L10 playing twice a month and probably longer to reach higher levels as paragon and epic encounters may take longer (higher XP budgets, PC damage doesn't scale as well with monster health at epic etc)
This has been borne out in my experience. My group meets weekly for about 4 hours. We usually get through two combat encounters in a session (or 1 combat and a social encounter or similar). We have been playing for a bit over a year and are nearly at L10.
Theoretically if this math continues (I don't think it scales quite the same way) and you can continue to finish 2 encounters in a session it will take aproximately 150 sessions to get to L30. at 26 sessions/year it will take a bit over 5 and a half years to level all the way to epic.
Addendum:
Here is a breakdown of time taken to Level from 1-30 assuming 2 encounter/session 26 sessions/year at 6, 8, and 10 encounter/level:
- 10 encounter/level -> 300 encounters -> 150 sessions -> 5.76 years
- 8 encounters/level -> 240 encounters -> 120 sessions -> 4.61 years
- 6 encounters/level -> 180 encounter -> 90 sessions -> 3.46 years
This gives you an idea at least of potential different rates at which you can level depending on how challenging your adventuring becomes.
I think you'll want to go with the Chaos Scar series. This is a DDI set of adventures for low level characters that should get you through levels 1-5. It's not a campaign per se, more of a sandbox, but should be no problem to string together if you're an experienced DM. I ran some of it with my newbie group, before that group ended, I had planned to run all of it.
I started with the D&D Encounters Keep on the Borderlands adventure; however, the adventure as written is just combat encounter after combat encounter, so I stretched it out and chopped it up a bit. You may have to find it on ebay if you want a print copy, I ran mine from a PDF.
Interspersed in that adventure I ran other side adventures from the Chaos Scar series, of which there are 15 for levels 1-4, which you can find here (DDI Subscription Required): Chaos Scar
1A Stick in the Mud
1B Den of the Slave-Takers
1C The Brothers Gray
1D Death in the Pincers
1E The Tainted Spiral
1F The Lost Library
1G A Chance Encounter
1H Eyes in the Forest
1I Elves of the Valley
2A Sliver's Call
2B The Shrine of Glass-Spire Forest
2C Dead by Dawn
2D The Hammer Falls
3A The Crawling Fane
3B The Splintered Spring
4A Glowstone Caverns
The characters were based out of Restwell Keep, which is detailed here (DDI Subscription Required)
The map of the Chaos Scar is great and can be found here (Free, as a .jpg)
There are two good resources for Chaos Scar info, both D&D Groups are old and outdated, but good info is here and here (Free)
I really liked the background of all the adventures that I ran and those that I read. I was hoping to use more of them but we stopped after 2 levels unfortunately. If I ever run another newb group I would probably use this series again.
After what's listed in the first link there are the following adventures:
LVL Dungeon# Name
- 4 178 The Crawling Fane Chaos Scar
- 4 180 The Pillar Of Eyes Chaos Scar
- 4 182 Vanguard Tower Chaos Scar
- 5 181 The Slaver's Stone Chaos Scar
- 5-7 192 Scarred for Life Chaos Scar
- 6 183 The Radiant Morn Chaos Scar
- 6-8 193 Rumble in the Valley Chaos Scar
- 7 184 Head in the Clouds Chaos Scar
- 7 196 Reflections of Ruin Chaos Scar
- 7-9 189 Scarblade Chaos Scar
- 8-10 186 The Runecutter's Ruin Chaos Scar
- 8-10 190 Pit of Delirium Chaos Scar
- 8-10 197 Heart of the Scar Chaos Scar
I hope this helps!
Best Answer
I would suggest you back into the level based on the amount of time you're willing to commit to character creation. In my experience, there tends to be a non-linear relationship between character level and time required to create the character from scratch. Let's create a simple model of how long it takes to make a character (assuming players are familiar with the process):
This gives us twenty-five minutes for a first-level character, and about two and half hours for a eleventh-level character. Your model may be different, and will likely have different values based on your group. Use your model to calculate how many levels of a character your group can build based on the time you've allotted for prep.
For example (using my model): You have a short game running about four hours, and you can only allot 45 minutes to character generation: you would calculate that your players can build level three characters in that time, so build a level three adventure.