If you want to run teh Seattle Missions in order, timelinewise:
There are three "prequel" CMPs that we ran at the conventions:
CMP 2010-01: Manhunt, CMP 2010-02: Copycat Killer, and CMP 2010-03: Ashes. Eventually we will have these all released in a bundle pack, and we actually have someone working on cleaning them up and organizing them so we can do that, but it's been slow going. By the SR Timeline, these adventures take place in Summer 2072.
The events from
Ashes get referenced a bit in the Missions, but it's not necessary to play it to understand anything that's going on (Part of the Ork Underground gets torched).
Copycat Killer, on the other hand, plays a more direct role and is teh first introduction of both MacCallister and Tosh to the Missions Campaign, and is a prequel to
SRM 04-05: On a Silver Platter. Because of that, we bundled
Copycat Killer with
Silver Platter for release, so if you buy the one, you get both.
SRM 04-00 takes place in December of 2072, officially, and introduces both plotlines. After that, the Missions take place once a month chronologically. So 04-01 is January 2073, 04-02 is February, etc.
That said, if you wanted, once you've run 04-00, you can stick with running just one plot or teh other. the odd numbered Missions (04-01, 04-03, etc) follow the "Buried Underground" plotline, which involves the Ork underground and Seattle Politics, while the even numbered ones follow the "Artifact Rush" plotline.
I suggest mixing the two myself, to give the PCs some variety, and it lets them build up a larger stable of NPCs as they go. But it's not necessary.

Bull