Gant diagrams are the best. But if you have not project management
or PERT program then with Excel you can make tricky tables like Sheet1
of the attached example.
Use
Tools->Auditing->Trace Dependents
                       Precendents

to draw arrows. See Picture in Sheet2 of the example.

                                Regards
                                               Ferenc Nagy
  |\   /~ ~~|~~~ [log in to unmask] Fax: (36-1)-395-9002
  | \  |    |    Institute of Isotope and Surface Chemistry
  |  \ |   -+-   1525 Bp. POB 77. Tel. :(36-1)-392-2550
  |   \|    |    http://alpha0.iki.kfki.hu/~nagyf
`-'    '  `-'    "The goal of the life is the struggle itself"