[Kabwe]

The only way you learn is to try. If you have a welder I say go for it. Practice on some scrap metal and get you technique down.

I butt weld everything whenever possible. Because it allows you to do a better job on the metal finish and use less filler. I only lap weld where the factory lap welded joints.

Panel fitment is important so get that panel to fit the best you can. When butt welding try to have a nice gap, if the metal is slightly touching that's fine. Your gaps should not be wider than the welding wire. Shaped your patch to perfection before you start welding.

You don't run a bead on sheetmetal you tack weld and move around a lot to keep the metal cool. What I do is tack the piece in and grind those welds, tack some more, grind, and tack until the patch is completely welded in. This allows the metal to cool and I'm also continuously working.

If you have access to the back grind your welds on both sides and use you hammer on dolly to stretch the metal back to its original shape (welding causes shrinkage, sometimes very little but always) as you are welding it in.

Oh yeah when you hammer on dolly to stretch the metal, hammer only the HAZ (heat affected zone). The haz is the area where the metal changed colors from the heat.

Just remember to go slow and try to keep that metal cool, cool is your friend.
I hope this helps.