Are you asking about pad sizes that can be etched and drilled at home, or pad sizes that can be easily soldered when assembling components on a board?
If you are concerned about etching and drilling a board, it varies A LOT depending on your fabrication methods. (Are you using photoresist, toner-transfer, direct milling, etc.) There used to be a Yahoo Group named something like "DIY PCB's", or "Homemade PCB's", etc, that may provide a good answer to your question.
If you are worried about manual soldering, it depends on what equipment you have and how much practice you have with it. If you don't have a moderate-priced, temperature-controlled soldering station (such as the Weller WES51, Hakko FX-888, etc) please invest in one. They tend to last a lifetime in hobby service if not physically abused, so a used unit that heats up and cycles its temperature control is generally a safe bet. Buy a few new tips, of common shapes, from the original manufacturer.
Your idea of elongating pads on through-hole devices has merit, and is definitely the way to go for SMD footprints. Most board fabricators require an annular ring of at least 8 mils - 10 mils on all through-hole pads. In my opinion, an additional 20 - 30 mils of exposed copper in the direction you will solder from is quite adequate for hand soldering, unless you are attacking the board with the chisel-tipped monster you use for sweating copper pipes, repairing radiators, etc. Learn to use the "Offset" feature in the footprint editor, so you add copper mostly in the direction where you need it, not around the entire pad.
(Yes, that means you'll have to learn about making your own footprints. Trust me - it's not that difficult, and you'll need to learn it before very long regardless.)
If you seed a search engine with strings like "printed circuit board design" you will uncover enough tutorials to keep you confused for a year or two. Some of them are oriented specifically toward hobbyists, and include the reasoning behind some of their recommendations.