I'm in your camp Tex! I love a fine cup of espresso. I haven't really used Starbucks, so don't know which coffee to recommend, but in all honesty, it would be pointless, as the choice of beans/roast is entirely a personal preference.
There is a technique to grinding and tamping the grinds, and as with everything, you get what you pay for (the same is true with an espresso machine). There are two main types of grinders, blade and burr grinders, with the burr grinders being the more expensive, but ultimately the more reliable grinders that will last long. They also provide a more even grind. They are more expensive, so if you have the money, go for a burr grinder.
Tamping is a technique you just have to get used to. The importance of filling the 'cup' or whatever it is called is to make it evenly distributed, and the tamp should be even to provide consistency through the coffee before you force hot water through it. Any fissures, or less dense parts of the coffee will make the water form a path of least resistance through and will end up in most of the water coming through this path and so extracting less flavour and essentially underutilising some of the coffee. In some cases, you can not use some of the coffee and overextract the remaining coffee, giving your shot a bitter and astringent taste. Tamping too hard will pack the 'cake' (for want of a better word) too much and will end up with it taking ages to pull a shot. Too little and water will flood through to quickly and not extract enough flavour.
The courseness of the grind also affects the way the shot is pulled in the same way that how hard you tamp does. There's no instructions to this. It's just practise and setting it on different settings each time you do it to get the 'goldilocks' setting - not too fine, not too coarse. I've bought some pre-ground coffee before, but have found that it's not ground anywhere coarse enough and the coffee ended up underextracted and weak with virtually no crema. As an example, on my grinder, the finest setting has it ground too fine and it takes the best part of a minute to pull a shot. The next setting is the best, with the following two settings (out of about 20) being too coarse for my espresso machine.
I love my espresso machine, and I get a far superior shot of espresso out of it than in pretty much every coffee shop I've been to that wasn't in Italy. Just out of interest, what machine did you get, steam or pump powered? I've got a
Gaggia classic baby
In the end, coffee (like the fine rioja I'm drinking at the moment) is a drink of love, and you should experiment with your machine and coffee to find what you like best. All this talk of coffee has made me wish I could have a nice warm cup of espresso, but as I'm about to go to bed, it's probably not a good job.
---------- Post added at 22:37 ---------- Previous post was at 22:35 ----------
But who needs guidance? what more of an excuse do you want for sitting around for a whole weekend drinking espresso until you get it just right!
Actually, that sentense is way better than anything that I wrote in all of my post
