Matt,

I'm fairly new to the woodworking world so I need some help with this
one. I'm wanting to purchase a planer or a jointer, but not sure which
one I should buy FIRST?

I only have a planer, and am strictly an amateur, so my opinions are
biased by those limitations...

A planer can usually accomodate a 12" or better width, while jointers are
usually limited to 6" or 8" widths. I frequently use my planer to plane
down 12" wide panels (glued up from smaller boards). I couldn't do that
with a 6" jointer. In fact, there are times the 12" width seems too
small.

A planer will make one surface smooth "parallel" to the opposite face. So
planing a board with a warp will make it smooth on both sides, but it
will still be warped. At least that's the theory. In my experience, I can
usually plane out any warping by flipping the board on each pass through
the planer. I have seen plans for homebuilt carriages that allow a planer
to work more like a jointer, but I haven't had a reason to do that so
far.

A common use for a jointer is cleaning up the edges of the boards to glue
up panels in the first place. But, I've glued up dozens of panels with
boards fresh from the tablesaw, and never had a problem. On a few
occasions (with slightly cupped boards for instance), ripping the board
on the tablesaw leaves a less than 90 degree angle on the edge. This
leaves a bit of cupping in the panel when it is glued up. But, running
the finished panel through the planer a few times flattens it out
beautifully. In some cases, I'll run the boards through my planer on edge
first (a few at a time) to clean up the edges, but I rarely find it
necessary.

Other than planing glued up panels, my planer gets used a lot to clean up
rough lumber. For instance, I took some old redwood 2x10's from an old
deck, removed all nails, and planed them down to make a variety of
shelves and a small bookcase. That old recycled wood made some beautiful
finished projects.

I also recycle a lot of 1x6 T&G pine and cedar boards leftover from
building our house. I typically cut off the tongues and grooves, glue
them into panels, and plane them smooth.

A couple of years ago I needed some 10' long clear cedar boards, 8" wide,
and 1/4" thick that I could bend into an arch for window trim. I
considered buying a bandsaw, but found it cheaper and easier to just buy
an extra 3/4" board and plane them down to the 1/4" thickness. The extra
board cost me $40. A bandsaw would have been well over $200. It turned a
lot of wood into shavings, and took a fair amount of time, but it was
easy to do on the planer and turned out great. A jointer wouldn't have
had the capacity to do this.

Anyway, my vote is for the planer. I suppose it depends on the type of
projects you build, but my planer is one of the hardest working tools in
my shop.

Anthony