This link may be useful for you: http://spanish.about.com/od/pronouns/a/indefinite_pronouns.htm

algo in something that you don´t know anything about him example: tengo algo en el zapato algun is something that you don´t know anything about him but you know that is 1 thing example: quedara algun libro para mi? alguno/ alguna is especific the genre in spanish there genre example: hay alguna casa? hay algun auto? casa is female auto, carro, coche is masculine algunos/ algunas says that are 2 or most things and the genre " as " "os" ask me if you don´t understand