Help With Combo Box Selection Being Determined By Entry In Another Field

first of all, i'm new to access. the only experience i have with it is reading the "microsoft office inside out", access section, and doing some research on the web.

i work for a school district and my boss has asked me to make a database with all our assets. i used to have everything in excel, but he prefers access, so here i am. what i'm wanting help with is making a combo box that lists manufacturers like hp, dell, etc., and then having the next field show a list of models depending on what was selected in the manufacturers field. so if i select dell, i want only dell models to show up in the combo list for models.

i can make the combo lists, but i don't know how to make it so that the entry in one field affects the list in another field. i've tried putting in lookup values, i've tried doing it with expressions in queries, and a few other things. i've tried searching google, and the forums and i've found things that are kind of similar to what i want, but doesn't do exactly what i want. so here i am...is there a simple way to do this? this isn't required of me, but now it's driving me crazy because that's the way i'd like to have it but i can't figure it out.

i'd appriciate any help with this.
thanks.