actually, I don't think you're in such a bad position. The work may not be exciting but you are in a position to do a variety of things from the way you describe the firm's setup so at least you're not going to be bored too soon.
Just ask questions if you're uncomfortable with something and try to learn whatever there is to learn from your employer. see how he manages his business for example.
And keep in mind that some form of disappointment or another was bound to hit you regardless of the economy - it's a normal thing to deal with when transitioning from school to work.

Larchinect, I tend to think any experience is good. Often you are able to learn what NOT to do. While you may pick up some sloppy habits, I seriously doubt you'll totally forget the strong things you've learned already, and as you gain experience and maybe go out on your own later you'll be able to determine which skillset is appropriate for which project.

Are you getting client contact now? That is a very valuable set of experiences. If your boss isn't being clear about what the client wants, what the program is, etc., ask if you can meet with the client yourself. And I think a site visit before any design work is pretty dang important (read: mandatory, assuming it's within an hour's drive!).

Looking for precedents is your choice; since the boss is letting you design, if that's how your design process works, then do it. I always look at precedents.

Also, you say you want to be an asset to your boss, which is admirable, and means you should not be shy about asking him/her what is expected of you on a project. There's nothing worse than sitting at your desk paralyzed because you're afraid to ask a question - that costs everyone time and money!

Good luck and congrats on getting a job!

I'm going to go ahead and disagree with ckl and lb.

'Any' experience is not necessarily 'good' experience.

Other than, of course, paying bills, there are a lot of jobs out there that are just huge time wasters. It's not uncommon for people to be in a position where they are merely asked to produce without thinking critically or even self consciously about what they are doing. This happens at large firms, as well as the mom and pop sized ones.

This of course can lead to a sort of dead end where one becomes the 'render girl' or 'model boy' or bathroom detailer. Which means that the person, after learning a certain amount, ceases to develope professionally and intellectually. However, by nature of the profession, more than likely this person is still putting in crazy hours, but because the job then entails little to no engagement it's more like being an assembly line worker.

In this instance, I would encourage someone to GET OUT, do something else that pays the bills but requires less time and freelance/work on one's own projects/ enter competitions/teach on the side. This way you're still developing/reading/drawing/thinking and not doing the same thing over and over for little reward.

Of course, you seem to be on the fence as to whether this particular opportunity could be really rewarding, or if it could be a blemish. I would encourage you to push [gently at first] and see if your boss and the clients are receptive or not. Is there a way you might link 'good' design to better performance, increased value, better lifecycle costs? Then you'd be speaking their language and you could, quite literally, prove that the standards and conventions do not always mean the 'best'.

jp is also right, but in the context of having been in this job only three weeks, I'd give you my typical advice regarding whether to stay or move on: give it a year. At the end of that time if you've learned all there is to learn, move on.

One really difficult thing about coming out of school is adjusting to the schedule. No more summer breaks, but also no major upheaval 3x/year, when you change professors/classes/studios etc. In the post-school world most people are on an annual schedule not an academic one, and it is a really, truly difficult transition to make.