Resource tiles are much, much better in Civ4 than they were in Civ3 (or than they are in Civ5).
Wow, that's an awesome start... though you could definitely utilize it better. First of all, you should have improved the Gems by now - in fact I would have improved them before the Gold, and certainly before the flood plain. Secondly, you should be farming that flood plain rather than cottaging it, because of the lack of food around. Third, especially with this awesome a start you should really be building a second Worker before a Settler.
If it were me, I would play a start like this as follows:
* Build first Worker to start with
* Pasture Cows, work (citizen 1)
* Mine Gems, work (citizen 2)
* Mine Gold, work (citizen 3)
* Build second Worker at some point around here
*
Maybe Farm Flood Plain, work (citizen 4)
*
Or just jump straight to chopping forests (with 2 Workers) while building Settlers and more Workers (all at size 3-4)
Anyway, in terms of what you have right now, you're better off with the second option (Cow/Gold/Flood Plain). But you should really get that Gems improved ASAP and work that too. Also get yourself a second (and probably third) Worker pronto.
Hope that helps.