Not a lot of jerks around here, buddy. Mostly me.
Ok, how to determine draw weight? Well, what kinda of draw weight are you comfortable with shooting? As you are tillering out the bow, you are essentially taking your board down from around 400 lbs of draw weight until whatever point you are satisfied with. Well, that's in a perfect world. In the real world sometimes you have to be satisfied with an underweight bow that just plain gave you fits during the tillering process! At least that's MY world! Your mileage may vary, offer not valid in Rhode Island, need not be present to win.
Now for building to your draw length, you say you shoot a 27" draw length. Good, that sounds normal for a normal sized human being. Often we have people making their first bows claiming they draw 31"!!! Real 31 inch draw lengths are pretty rare...they exist, just not on every block!
Before we can determine the length of the bow based on draw length, we need to know what style of bow you might have in mind. For instance if you want the Classic American Flatbow with the narrow unbending handle, wide/flat limbs...well then just double your draw length and add a minimum of 10% for safety. (27+27+ 5.4 = 59.4...but you can call that 60 inches from nock to nock). And that is your minimum length, go longer for safety until you become more proficient at making these bows.
But if you want a bend-thru-the-handle "D" style bow, you can simply double your draw length for a 54 incher. But again, this is the mkinimum. Go longer for safety and also find out that longer bows are inheritantly more accurate.
Spend an evening running around in the Bows section looking at all the different styles and variations on styles of bows. Then when you have decided on what kind of bow you want to build, FORGET IT! Seems like everyone wants to build a laminated, highly recurved, Mongolian/Turkish horsebow for their first bow. Now go back and look at the simple bows. Simple bows are not easy either, but errors in tillering are easier to see and correct before it blows up on you.
Left handed? If you are careful and get the string centered in the handle, it's automatically a left handed bow. And simultaneously a right handed bow! And if you make the limbs symetrical, it works upside down, too!
Just never expect a plain wood bow to stand up for being strung backwards.*
Good luck, and don't be afraid to post pictures!
*And there is an exception to this rule as well. And technically it's not made of wwood, though it is an all natural material.
