Greetings all.... I have several flowering annuals and veggies from which I would like
to collect the seeds to plant next year.... these include

Annuals

Marigold (several varieties)
Flowering Vinca (Catharanthus roseus), also known as Madagascar periwinkle
Coleus (several varieties)

Veggies

Tomatos
Melons


Here's my question,... I am almost totally clueless about what the seeds look like,
and how they are harvested....

With the flowering plants (marigold and vinca) do the flowers produce the seeds and do
I wait for the flowers to die on the stem before removing and storing.

Tomatos and Melons - are those seeds actually the propagatable seeds for the plant

(Look when I said DUMB.... I mean REALLY DUMB, but at least smart enough to know
which questions to ask).

So what does one look for when collecting the seeds and how should they be stored
for use the following year. ( I know, its easier to buy the seed packs, but I'm
trying to fill gaps in my education).

Thanks for your help ( and patience !!! )

Peter