Framing and Sub-Flooring - Pre-Fabricated Truss for my Patio roof

I am ordering Pre-Fabricated Truss for my Patio roof from a Truss manufacturer. Size is 32X20 feet per design below. They are using 2X4, 24 OC total of 11 trusses. Are there any thing I should look for in terms of design/Specification or how the trusses are made? I find the Truss is a much cheaper way to install compared to the stick frame. Appreciate input from anyone who has knowledge of roof trusses. Thanks
<a href="http://s80.photobucket.com/albums/j165/SethNaga/?action=view&current=Truss.jpg" target="_blank"><img src="http://i80.photobucket.com/albums/j165/SethNaga/Truss.jpg" border="0" alt="Photobucket"></a>

Is the patio free standing? If not, how will you treat attachment points to the existing structure? They will ship you 9 trusses as you have pictured, plus two end trusses so you can attach gable end lumber to it. You will need to provide for support 1' out from the edge of the structure for the two end trusses, so be aware. You will also need to attach look outs to the outside trusses

Thanks for the response. The plan is to attach the roof framing to my existing wall studs of my home. They have to remove the siding. The gable will be supported by 3 6X6 posts on each side of 20 foot patio width. No posts along the length of 31 feet of patio

In that case, have you figured the overhang? If you space them equally, you will wind up with no overhang. One truss against the house, and 10 spaced equally at 24" will be exactly 20'. Generally the truss mfg will give you a layout sheet. Have they done that yet? Make sure you get one so you will be informed on the placement.

Thanks; here is the layout of the roof. 10 regular trusses and one end truss as below. So I thought this covers the overhang?
http://i80.photobucket.com/albums/j165/SethNaga/end_Gable.gif
http://i80.photobucket.com/albums/j165/SethNaga/patio_Design.gif

The overhang is the roof sheathing and roofing material with a barge and rake trim boards overhanging the gable truss. It can be held up by blocking (at right angles to truss) or by lookouts (2x4's) flat, at right angles and spanning the gable truss,(notched into) nailed to the truss next to the gable. Some builders run the plywood alone over the gable to create the overhang, a system that will sag. Again, you want a R-1- studded for your gable away from the house. (as there will not be support under the clear span between end bearings). As I said on the other site- use 2x4's as top chord against the house instead of the 10th R-1. Only order 9, and one stressed and studded- 16"on center, unless atached to the house cantilever. Be safe, G