• Stuart Brorson's footprint footprint guide
• PCB manual
• The PCB FAQ: pcb_tips.
• The PCB Quick-Reference has info on footprints
• PCB Footprint Naming Conventions : read this to learn how to name your footprint files.

• There are two types of footprints: M4 and NEWLIB.
• The best tools for creating footprints are PCB (wysiwyg), TEXT EDITOR (fast, accurate), SCRIPTING (powerful).
• For drawing footprints in PCB, refer to: (: insert a WYSIWYG footprint creation guide)
• For writing footprints in text, refer to Footprint Creation for the Open-Source Layout Program "PCB" written and maintained by Stuart Brorson
• For Scripting footprints see the footprint generators page
• Other things you may find helpful: calculator, paper+pencil, datasheets, calipers, spreadsheet.

• http://www.nxp.com/package
• http://focus.ti.com/general/docs/packaging.jsp
• http://www.maxim-ic.com/design/packaging/
• http://www.national.com/packaging/folders/pkg_index.html
• http://www.irf.com/package/
• http://www.onsemi.com/PowerSolutions/supportTechDoc.do?id=1165
• http://www.analog.com/Analog_Root/Packages/Packages_Home/
• http://www.linear.com/designtools/PkgInfo.jsp

: pcb_tips covers a lot of Footprint material. This page and that page need to be reconciled!

• The place to share symbols and footprints is gedasymbols.org

• You can find many PCB footprints at John Luciani's footprint page

• You can share gEDA footprints at Open Circuits.

“Yes, totally. This is how you create oval shaped copper around pins, or funny shaped pads (e.g. square at one end and round at the other) by overlapping two or more pads.”

Simply add a pad on top of your pin and give them the same pin-number. If the soldermask is kept off both pins, and they overlap, they should appear as one pin on your board.

“Odd as it sounds, this can be necessary for some edge connectors. … but how do you do it???”

You can do it by making two pads at the same position and same pin number, but the second one with the flag “onsolder”. Like in:

Pad[ 10mm -3mm  10mm 3mm  2.0mm 0.5mm 0.2mm "1" "1" "square" ]
Pad[ 10mm -3mm  10mm 3mm  2.0mm 0.5mm 0.2mm "1" "1" "square,onsolder" ]

Do a 2-sided pad as above. If you want the shape of the connector pad to be square at the edge end and half-round at the pcb-interior end, use two overlapping pads per side, like in:

Pad[  0   -3mm   0   3mm  2.0mm 0.5mm 0.2mm "1" "1" "square" ]
Pad[  0   -3mm   0   5mm  2.0mm 0.5mm 0.2mm "1" "1" "" ]

Pad[  0   -3mm   0   3mm  2.0mm 0.5mm 0.2mm "1" "1" "square,onsolder" ]
Pad[  0   -3mm   0   5mm  2.0mm 0.5mm 0.2mm "1" "1" "onsolder" ]