Akihabara is where all the Giants of modern Electronics are. The tall buildings along the streets with the big neon signs impress. Akihara is dubbed Electric Town and got its reputation after World War II when black market goods were sold here.
The best place to start browsing the shops is Chuo Dori, the main street. Sporting goods are located in Yasukuni street, books shops in Jimbocho.
Furthermore there are two important shrines you can visit, the Yushima and the Kanda. Both were distroyed in the big 1923 earthquake but rebuilt in the thirties with good taste.