I would recommend these sites for a clear explanation of verbs of motion: http://masterrussian.com/verbs/verbs_of_motion.htm <-- Overall introduction (good to help differenciate between идти и ходить) http://learnrussian.rt.com/grammar-tables/verbs-of-motion-with-prefixes/ <-- Explanation of prefixes http://www.russianlessons.net/lessons/lesson16_main.php

All of this words have a lot of meanings. Ходить is means ability too. For example: I can walk - Я умею ходить. And Ходить means to go - I got to go to work just like every day = Мне нужно ходить на работу каждый день. To attend - I go to the gym = Я хожу в спортзал. Идти usualy = to walk, but not always. I have to go = мне нужно идти. Сходить means go to (usualy walk) somewhere and come back. But this word also have some other meaning. Уходить - leave, go off - means motion from some place (not only walk) Приходить - come - means motion to some place

Подборка видеоуроков на эту тему https://www.youtube.com/watch?v=qVqdzA__9mQ&list=PLrIkLgUgjNHfT0WWIRfvoGuhxicyyqFGc

Yes , MamaPata is right . There is a lot to write here , you can easly google the subject. Also it's best to approach non-prefixed verbs of motion at first. get understanding , learn the conjugations of pairs идти - ходить/ ехать - ездить. And only after having studied the aspect, go to prefixed verbs.

Ходить = to walk. All other mentioned verbs are the forms of the verb "ходить". And yes, they are all the verbs of motion.