The purpose of this study is to see if 7 drugs, some of them given at higher doses than normal, are safe and tolerated by young patients with AIDS who have failed to respond to other treatments. The study will also see what effect taking several anti-HIV drugs together at high doses has on the body's ability to fight HIV infection. The 7 drugs that will be given in this study are stavudine (d4T), didanosine (ddI), lamivudine (3TC), nelfinavir (NFV), ritonavir (RTV), saquinavir (SQV), and nevirapine (NVP).