I shoot a recurve and have experience only with aluminum and carbon arrows. Later this year I will get a longbow and intend to shoot heavier wooden arrows. The main question is, do I need to maintain arrows? Do they need to be straightened? I have seen some things about making arrows, but once you have a finished arrow, what do you need to do with them? Do they warp or get twisted? Please advise!

Good wood shafts generally hold their straightness once they are finished and are stored so they don't lean.  I just throw mine in a box and don't generally have an issue with that.  Lighter spined shafts can be bent went pulling them out of targets if bent in the hand.  Some longbows can tolerate over spined wood shafts and others not.  I would not go much over the weight of the bow in a Hill with a dacron string for example.

i store my wooden arrows in a storage case with foam dividers - probably not necessary, but it doesn't hurt.  you should check your arrows occasionally for chips and scratches in the finish and patch these areas with super glue or a fast drying polyurethane. chips especially tend to spread if you don't fix them.  you might also find when you install points/broadheads on larger shafts(23/64) that there is a small ring of bare wood at the base of the point where it didn't totally cover the taper.  seal that up too.  bare wood and water - even cedar - don't mix.

I shoot nothing but wood arrows, primarily for the satisfaction of making and shooting them.
Cedar is the easiest to straighten and maintain.
In California we often don't put any finish on them at all....they are called 'summer arrows'.
A piece of advice.......don't start unless you really, really want to-it is highly addicting!

Good cedars will stay straight.  I usually keep mine in a back quiver, hanging on the wall.  Order good shafts from a reputable source.  If you buy weight and spine matched you will shoot with anyone and any arrow.

I used to make them up and give them away cause I had shafts that weren't spined right for me. Like Bjorn says, it's addicting.

My two favorite attributes about cedar are; They smell good when you break them and they have a "feel" when shooting them that carbon or aluminum do not have. Kinda like they abbsorb the bows power....

If they keep going up in price the way they have been for the last 5 years you should invest heavily!

Oh Biggie, I like that, Absorbs the bows power.

As always: a sticky subject.

To answer your question, "What do I need to know...," pick up a copy of Traditional Bowhunter's Handbook or Traditional Bowyers Bible III.  They will tell you what you need to know about wood arrows and a lot of other stuff traditional.

http://hildebrandarrowshafts.com/