Your Dell Inspiron 1501 takes a bog-standard 2.5" SATA HDD, and there are plenty of options as to what you can install, including a Solid State Drive if you really want to lash out.
If you can wield a screwdriver without injuring yourself, and can upgrade RAM, then I don't think a HDD replacement job will overwhelm you.
Dell Inspiron 1501 upgrades -
Top Crucial.com Ram Flash Memory Upgrades (click on, "Show all compatible Internal Hard Drives")
Remove HDD from Dell Inspiron 1501 -