Find Ancestors

hi im trying to do a family tree,im new to this,right where do i begin,my fathers side is SMITH and my mothers is ROBINSON but it goes back to bayford and that.my dad is JOHN SMITH born in 1952 in hackney london,he has 3 brother and 3 sisters,my grandad (on my dads side) was ROBERT ALFRED SMITH born 28th jan 1912,born in bethnal green london,but sadly died in july 1988 in luton beds,but he was married to NELLIE MCcARTHY.born 6 may 1911 in st pancras.they moved to bedfordshire and had a family.my g grandad was JAMES HENRY SMITH born 1 june 1876 in bethnal green london,he died 7 may 1939 in hackney london,buried in manor park london,he was married to EMMA STOREY on the 25 dec 1895she was born 17 nov 1878 bethnal green london,,he last address was 260 rushmore rd,london,above a shoe shop he owned.emma died 18 april 1960they had 9 children,my g g grandad was JAMES HENRY SMITH born 8 feb 1857 in bethnal green london,he married CAROLINE STOKES on the 18 mar 1876 ,,she was born 4 oct 1857 in back of 12 stoke st birmingham warwickshire, they also had 9 children.thats as far as ive got i think so far,all i know at the min about my mothers side is her dad was called GEORGE ROBERT ROBINSON born 8 dec 1913 london area but died 13 june 1998 in luton beds,he married VIOLET ANNE BAYFORD born roughly same time but died in 1994 in luton beds,they had bout 6 children,they are from grays essex area b4 movin to toddington then houghton regis,could b more moves in between,not sure.i know its a long shot but if any body could help id be gratful,thank you