Getting started - Interfacing questions

I'm quite a newbie with Postgresql - or any databases whatsoever, for
that matter. I've been studying the archives and documentation for the
past couple of weeks and find it quite fascinating.

I must say that my interest is totally personal. My initial project is
to convert my personal record-keeping system from a flat random-access
disk structure to a genuine DB. My needs for this are quite modest,
probably a couple or so hundred records for the year - not really in the
category for needing a true database, but it appears that the
possibilities for making reports would be limitless. The current
structure of my system is something like this.

a payor/payee file, containing the names of people/businesses with which
I do business.
Two Categories files, (income, expense) - the various categories such as
Labor, Supplies, etc.
A data file describing the date, descr, payor/payee, Category,
cost/income value

The payor/payee and the Category file entries also have fields for the
current totals for the respective element, which was updated with
each transaction. This is no longer needed in my current system, nor
would be for Postgresql, but the program was originally written for
a 2 Mhz 8-bit computer, and I didn't want to wait for that system to
scan over the whole system each time I did a query. Oh, FWIW, the
program is written in "C".

Currently, the reports I do are:

1) An itemized list for each transaction, broken down by category
2) A summary for the totals for each payor/payee
3) A summary for each category
4) A summary with incomes/expenses broken down by the month.

Actually, at this point, I've been able to basically get most of what I
want with psql, with my experimentation, although I'd need to do some
honing to what I've got before I could get a final working model.

The question I've not yet been able to satisfactorily answer - I suppose
I could answer it myself with enough experimentation, but would appreciate
a little jump-start if possible - is the correct interfacing method. As
I said, it appears that psql _may_ give me all I need, but what is the
normal approach to operating a database? Are real databases actually
run from psql, or is it better to develop a front-end to the whole
setup? One note, in my case, what I'm developing is strictly
single-user. If need be, I could do my inserts straight from the SQL
command, although a forms-type interface (as I have in my current setup)
would be nice.

The biggest drawback I'm seeing with psql, unless there's something I've
not discovered yet, is in making neat-looking reports. I'm not looking
for anything extremely fancy - just easily readable and easy to
interpret.

I installed pgaccess but I'm not sure it will do what I want. I
downloaded the datavision sources, but am missing some classes and I
don't know if I want to fool with java or not.

So, it all boils down to this - can a serious database be run from psql
or is it better to use something else? I believe I could write an app
in "C" without much trouble, using my current program for a pattern for
the user interfacing, and I'm even thinking about trying my hand
at perl or python, but it would be nice to do it all from psql if
possible.

Thanks for any suggestions anyone can provide.