But I'm no expert, can someone describe the difference between ash, maple and alder?
From the Warmoth site:
Alder (Alnus rubra):
Alder is used extensively for bodies because of its lighter weight (about four pounds for a Strat® body) and its full sound. Its closed grain makes this wood easy to finish. Alder's natural color is a light tan with little or no distinct grain lines. It looks good with a sunburst or a solid color finish. Because of its fine characteristics and lower price, Alder is our most popular wood and it grows all around us here in Washington State. The tone is reputed to be most balanced with equal doses of lows, mids and highs. Alder has been the mainstay for Fender bodies for many years and its characteristic tone has been a part of some of the most enduring pieces of modern day contemporary music.
Ash (Fraxinus americana):
We have two very different types of Ash: Northern Hard Ash and Swamp Ash (Southern Soft Ash).
Northern Hard Ash is very hard, heavy and dense. A Strat® body will normally weigh 5 lbs. and up. Its density contributes to a bright tone and a long sustain which makes it very popular. Its color is creamy, but it also tends to have heartwood featuring pink to brown tints. The grain pores are open and it takes a lot of finish to fill them up.
Swamp Ash is a prized wood for many reasons. It is a fairly light weight wood which makes it easily distinguishable from Hard Ash. A Strat® body will normally weigh under 5 lbs. Many of the 50's Fenders were made of Swamp Ash. The grain is open and the color is creamy. This wood is a very nice choice for clear finishes. Swamp Ash is our second most popular wood. It is a very musical wood offering a very nice balance of brightness and warmth with a lot of "pop".
Maple
(Acer saccharum-Hard Maple):
We offer two types of Maple: Eastern Hard Maple (hard rock maple) and Western Soft Maple (big leaf maple).
Hard Maple is a very hard, heavy and dense wood. This is the same wood that we use on our necks. The grain is closed and very easy to finish. The tone is very bright with long sustain and a lot of bite. This wood cannot be dyed. It looks great with clear or transparent color finishes.
Soft Maple
(Acer macrophyllum):
Western Maple grows all around us here in Washington state. It is usually much lighter weight than Hard Maple but it features the same white color. It has bright tone with good bite and attack, but is not brittle like the harder woods can be. Our flame (fiddle-back) and quilted bodies are Western Maple. This type of maple works great with dye finishes.
Hope this helps!