The element lead has the electron configuration [Xe] 4f14 5d10 6s2 6p2. This formula says that lead has all the electrons of xenon as well as the electrons listed after [Xe].
The 6s and 6p electrons are in the outermost shell, and are therefore the valence electrons. By convention, they are written last in noble gas configuration. When finding an atom from its noble gas configuration, start at the noble gas listed, then add the electrons listed. Alternatively, it may be easier to look at the listed subshells and determine which one is incomplete. If a subshell is incomplete, then that atom must be in that part of the periodic table. For example, lead has only two electrons in the 6p subshell, rather than the six that 6p can hold. Therefore, the atom with this configuration must be in the p block of the sixth period of the periodic table, which does indeed hold lead.