I'll ask here since my question doesn't really seem to fit anywhere else.

I'm trying to decide if I have a hope of tackling this project of mine. I'm looking to make a database for my contracting company that keeps track of our invoices, suppliers, jobs, products and pricing, etc. I had been fooling with MS Access, but eventually I bought a book on SQL, and to make a long story short, decided Postgres was a better fit for me.

I only vaguely knew what a database really was before then, but after some reading, I feel I have a decent understanding of how the relational model works. I created an entity-relationship diagram for what I want to track, and translated it into a schema that makes sense to me (8 tables, 3 of them joins), and seems to function acceptably when I put dummy values in. I have an ok understanding of queries and views.

Besides that, I know very little actual SQL, but I've had a glance at some examples and it makes sense so far. This is where I hit my roadblock: I now realize that I want a user to be able to enter invoices, or print a monthly summary, etc. This means I need to be able to take the user's input, and have the database return the data they're looking for (or add a record, etc), and I can tell already that there is going to be a lot of back-and-forth translations between what makes sense to the user, and what makes sense to the database (e.g. I can't just SHOW a user one of the join tables that's full of integer foreign keys).

So I now see the problem of interfacing a graphical front end with the database. So here are my skills, and maybe someone who really knows this stuff can tell me what my best bet is (my end goal is something an average data entry clerk would have no trouble with and can produce the reports that business owners might want to see). I spent six years in university studying math/physics, so I appreciate the logical/mathematical side of database schemas. I'm usually a quick learner, but I'm lacking in experience: like I said, beginnerish SQL knowledge. I did take three programming classes in high school (all in C++), and one in university (Basic), but that was a decade ago.

I don't have any timeline on this (pet project), so what could I hope to accomplish in a month or two - or what's the most efficient way to get to what I want? I don't know if I need to learn a new programming language, or maybe there's some "tool" that PostgreSQL has I don't know about, or maybe Access is more than enough... I'm not sure, but the whole idea of streamlining user<-->database communication seems like it would be such a universal problem that there would be loads of easy solutions by now. Ideas?