egh. help?

[forsakentruth.livejournal.com]

so, i'm pretty new to sewing.

first step is admitting right?
i've made a few skirts, and a
couple of purses.. turned out
great. then my bottom thread
cartridge ran out.. had to
replace it, and i have no idea
how. does anybody know what im
talking about, so much that they
could help me - or maybe if you
think you could help me if i
explain a little more? i want
to make some things for christmas,
and my family sucks with crafts...
so i'm stuck, any ideas?