No worries, Unit88. A lot of people are more or less completely new to DF, so questions that seem silly are often sincere results of newbiness. Since we want to infect as many as possible with DFitis, we try to draw them in.
The general recommendation is to start with Plump Helmets on embark, because they are versatile and have high productivity. I've switched my profile to grow Cave Wheat and Sweet Pods for one season each and Plump Helmets the other two, with Pig Tails on the side for threshing only. I never bother with Quarry Bushes or Dimple Cups because neither can be brewed.
There are two reasons I rotate crops over seasons from embark:
- Seed availability. I start with 9 seeds of each usable crop, but seeds can easily be locked up in unprocessed produce, so by switching to a different crop the next season I get a fresh set of initial seeds for that crop. Later on when your farmer gets some skill you shouldn't have any physical lack of seeds. I tend to build my still in spring or summer, but often don't appoint anyone to use it until autumn, which means seeds are released only through dorfs eating the produce raw.
- Booze variety. Call it a fixation or role playing, but I try to give the dorfs the widest possible range of booze to chose from.
Whether you grow overground crops or not depends on play style and the nature of the biome. You can often find a fairly wide variety of plants topside through Herbalism. I normally designate the whole map for plant gathering on embark and let unbrewable plants be cooked. Apart from brewable plants, I also tend to have a 3*3 plot with overground threshables (rotating over seasons if several types are available). For the sake of it, I also collect dye plants, but just keep a small number of them. The initial plant gathering designation doesn't catch everything, however, because some plants are season dependent in the wild (various berries, for instance), so I try to complement my stock using manual single plant designations later on.
At a later stage, I try to build an orchard, i.e. a completely enclosed several z levels high area in which I chop down all trees that are not fruit bearing, with the aim of getting one of each kind. This serves very little purpose from a practical perspective, though, since you should have more than enough booze as it is.
One problem I have is to balance the food and booze production, because I tend to get a huge over production (having more than 10 years worth of food and booze in stock is a bit much).