Where can you store Pokémon in Black and White

Suite101 has a well written guide on the location of the Seven Sages.

The only sign you get of Ghetsis is a message from his Shadow Triad that he's disappeared for the time being as you try to cross the Marvelous Bridge, east of Nimbasa City. They'll give you the Adamant, Lustrous and Griseous Orbs, all formerly held by the main legendary Pokémon of Diamond, Pearl and Platinum, before disappearing. Consequently, you can't actually catch Ghetsis.

First up, then, is Sage Zinzolin. Remember when you fought off Team Plasma in the Cold Storage area in Driftveil City? Zinzolin is there, way back in the same freezer where you found the whole team huddled in a mass. He gives you TM01, Hone Claws.

Second is Sage Bronius. He's probably the most annoying of the sages to find, as he's hiding in the depths of the Chargestone Cave, an area you have no real reason to revisit otherwise. Look in the southern reaches of the bottom level of the cave. Be ready, as he's protected by two Team Plasma grunts. You'll get TM69, Rock Polish, from him.

Third is Sage Rood. He's in an isolated spot way at the western edge of Route 18, just off Route 1 at the beginning of the game. He'll give you TM32, Double Team.

Fourth is Sage Ryoku. Descend into the Relic Castle again and you'll discover a new set of passages you can enter. Inside you'll find a maze, and after getting through the maze (which isn't terribly difficult) you'll find Ryoku. He'll give you TM04, Calm Mind.

Fifth is Sage Gorm. Go back to the Dreamyard east of Striaton City, enter the basement, fight off the trainers there if you haven't already and make your way to the second ruined building at the other end of the passages. You'll find Gorm waiting, and he'll give you TM75, Swords Dance.

Sixth and last is Sage Giallo, the only sage in the post-game sections of Unova. Teach Waterfall to one of your Pokémon and ascend the falls scattered around Route 14 to find him. Giallo gives you TM08, Bulk Up, before Looker thanks you one last time and carts the villain away.

You can find them on Bulbapedia. Here are the most important:

Aesthetic changes

• New locations such as Aspertia City, Virbank City, Floccesy Town, Lentimas Town and Humilau City have been added to the game.
• New characters are introduced.
• All Unova Gyms receive redesigns, including newly remixed music.
• There have been several changes made to existing locations, such as Driftveil City and Nimbasa City.
• Several attacks have received new battle animations.
• The battle menu and the C-Gear have been redesigned.
• The Unova Pokédex has been expanded tremendously to accommodate older Pokémon.
• In place of Cold Storage, there is now the Pokémon World Tournament.

Storyline changes

• The player no longer starts in Nuvema Town, instead starting in Aspertia City.
• Chili, Cress, Cilan, Lenora and Brycen are replaced by Cheren, Roxie and Marlon as Gym Leaders.
• Bianca gives the player a Starter Pokémon.
• A new Team Plasma has formed, and is run by Ghetsis.
• Iris is the new Champion of Unova.
• Ghetsis returns and plans to freeze Unova with Kyurem.
• Neither the version mascots Black Kyurem or White Kyurem can be caught within the story, but can be obtained post-game by following certain requirements.
• Another new attraction introduced is the Pokéstar Studios, located in Virbank City, where the player takes part in many different movies.
• Several areas that were previously limited to the post-game of Black and White are now part of the main story. In contrast, some of the areas that were formerly part of the main story are now limited to the post-game.

Gameplay changes

• A new feature called the Memory Link is introduced, which reveals flashbacks from the NPCs that shed light on events that happened between Black and White and Black 2 and White 2.
• Many TMs and all but one HM are received in different locations.
• The Move Tutors are back, and as with Pokémon Platinum, they teach most of the moves that were in that game for Shards, but here they all ask for shards of a specific color. They also teach many moves that lost their TM status.
• A number of legendaries from Hoenn and Sinnoh (excluding the Weather trio and Creation trio) can be found in the post-game.
• Zorua and Zoroark, which were previously accessible through Nintendo events only, can now be found within the game without any special requirements.
• Hidden Grottoes are introduced and scattered all over Unova, giving access to many items and Pokémon with their Hidden Abilities, many of which were previously unobtainable.