Welcome to the PMC official thread for summon, setblock, blockdata, and other commands. Here you can, ask for help with these, and show of your creations with these commands.
These commands are very powerful, but are also fairly complicated. To get you started, I've included links to helpful pages, and some specific info on the setblock command.
Set Block Structure
/setblock x y z block data method dataTag
x y z are the coordinates of the block
Block is the TileID of the block (includes id:0 now!)
Data is the block data (i.e. 5:1 spruce wood)
Method is one of three things: keep, replace, or delete
-Keep spawns the block at the coordinates.
-Replace replaces the block at the coordinates with the block ID.
-Delete removes the block at the coordinates and then spawns the new one in
dataTag is tile entity data.
Here are some very useful links. Thanks to poltercreeper, Spellguard, Myself, sigurd4, and Deathassassin05, for finding them.