I found this for Jessica and Hunter they are member of my 4-H club that raise Market Lambs.
this article just for you. Check It out It is good stuff.
This is a great must Read for the first year, or like me someone who know nothing about raising market lambs.
By Mike Neary  Extension Sheep Specialist  Purdue University      To read the full article click this link 
Choosing what breed or breeds you want to raise is an     important decision. You need to keep in mind that every breed has strong points, as well     as weak points. Therefore, match up breeds with your particular situation. commercial     white-faced and black-faced can also be used for market lambs. Make sure you know     something about the breed character and traits of whatever breed you are choosing. Contact     your state or national breed association for information about breeds you are interested     in.
When choosing a producer to buy lambs from some important     points need to be considered. Primarily, is the breeder an honest, respected person that     will truthfully answer questions and assist you should a problem arise? Good producers     back their product and help 4-H participants with their questions and offer advice.
When selecting lambs, keep in mind the final objective;     production of a lamb with a high quality, lean, muscular carcass that is practically and     economically produced. Most lambs should be slaughtered in a weight range of 105 to 130     pounds. Ideally, lambs should be slaughtered when they have from .1 to .2 inches of     external body fat. This fat thickness range ensures that carcass quality is adequate, with     minimal amounts of excess fat trim. Therefore, the final weight achieved when lambs are     finished will vary depending on breed, frame size and nutrition.
A common fault in selecting market lambs is to select lambs     that are of an extreme in a particular trait. Single trait selection for any type of     livestock can quickly lead to decreased usefulness when other traits are measured.     Therefore, lambs should be selected that are "well rounded" or complete. these     lambs would be above average in all respects, rather than exceptional in one trait and     below average in all others.
What is a complete lamb? A complete lamb is one that is     above average in muscling, of adequate frame size to have economical gains and finish at a     market acceptable weight and is structurally correct.
When evaluating a young lamb to predict future muscle     thickness, you need to keep in mind carcass economics. The highest priced cuts from a lamb     come from the hindsaddle, or from the last rib back. Your lamb should show evidence of     depth and width through the loin, fullness and length through the rump, with a full,     muscular leg and stifle. Also, the forearm area of lambs and fullness behind the shoulders     are good indicators of future muscle development. A lamb is born with all the muscle     fibers it will ever have, feeding or exercising will not make a lamb into something it is     not genetically capable of being.
Frame size in lambs is used to predict growth potential and     to predict size (weight) when properly finished. Usually, lambs should be from average to     large in frame size, for their breed, for economical gains. Very small and very large     frame size lambs should be avoided, as they often finish at weights that are not market     acceptable. Frame size is often thought of as just height, when actually it includes body     length and body capacity. Frame size can be compared to a rectangular box, with height,     length and total volume all making an equal contribution. Ideally, lambs should be long in     the hindsaddle (loin and rump) region.
Structural correctness refers to several traits. Certainly,     your lambs should have sound mouths, normal eyes, and be free of any abnormalities. Feet     and leg placement should be square with normal width and straightness. Furthermore, lambs     should have strong pasterns and no feet problems. Do not buy lambs that limp and if a     producer has footrot problems in his flock, consider buying from someone else.
Balance or eye appeal is also desirable in your lambs. Eye     appeal is a subjective measurement, but generally, lambs should be level in the top line,     straight and square over the rump, and not have extreme coarseness through the shoulder,     neck and brisket area.
When buying your lambs, make sure they are within a     manageable weight range. They need to be at least two months old and heavy enough to     attain their finished weight by fair time. Most lambs will gain from 0.5 to 0.75 pounds     per day. However, do not make the mistake of buying lambs that are too heavy. Lambs that     are held at maintenance too long get stale appearing. Ideally, your lambs should be within     a weight range that will allow for normal growth to reach market weight by fair time.