I know it is desired to get the blue buff for Ability Power (AP)-base champions and the red buff for Attack Damage (AD)-base champions and baron buff is good for everybody. I think blue buff at least increases your mana regeneration and red buff your health regeneration. So far I don't have any experience with maps (and therefore its buffs) other than Summoners Rift – I would like to know about these too.
What do the buffs affect in detail (preferring concrete numbers)?
Best Answer
Summoners Rift buffs:
Information applies to Pre-season 5 and can be subject to change
Crest of Cinders (Red buff)
Granted by killing the Red Brambleback in either the Northern or Southern jungle.
Crest of Insight (Blue buff)
Granted by killing the Blue Sentinel in either the Eastern or Western jungle.
Both red and blue buffs last for 2 minutes without Runic Affinity and 2:24 minutes with it.
If slain, buffs held by the newly dead transfer to the killer.
Hand of Baron
Lasts for 3 minutes with or without Runic Affinity.
If slain, the buff is lost but not transferred unlike the blue and red buffs.
Dragon Slayer
This is a permanent team-wide buff that stacks with the number of your team's dragon kills.
Twisted Treeline buffs:
Crest of Crushing Wrath
Granted by killing Vilemaw, the boss monster located at the top of the map.
(No source can be found with exact details, but this unspecific info was found on the wiki)
Lasts for 2:00 minutes or 2:24 with Runic Affinity.
If slain, buff is lost and not transferred (same as Hand of Baron on Summoner's Rift).
Altar buffs
One AltarCapturing an altar will give +80 gold to all players on the capturing team and vision of the altar
Buff is permanent as long as you own the altar.
Altars first open at the 3 minute mark and are locked for 90 seconds after being captured. Once unlocked the other team can capture and lock it for themselves, but the same altar cannot be captured by the team that already owns it.
Crystal Scar (Dominion) Buffs:
Shrines
These areas are neutral, so both teams can utilize them.
lasts 10 seconds or 12 with runic affinity
Health Relics
These areas are neutral, so both teams can utilize them.
Greater Relic / Storm Shield
Increased champion model size. - A shield of 212.5 (+12.5 x level). - Passively detonate a lightning blast inflicting 90 (+10 x level) magic damage on champion auto attacks and damaging spells.
Mark of the Conqueror
This buff is granted to the first team to complete a "quest" on dominion.
50 seconds or 1 minute with Runic Affinity
Proving Grounds (ARAM) Buffs:
(Same as Dominion Health Relic)
Health Relics
These areas are neutral, so both teams can utilize them.
FORMATTING TAKEN FROM @theorise