the oddsmaker's dont always have the best number, there are too many games for them to line for them to have the best number on all games. A good starting point for newbies is on regional action on college games. There is a lot of info that is available to locals before the books adjust their lines (often they never do). For example, I live in Austin so I get a lot of info on UT, ATM, Baylor, Rice, OU, $pur$, etc. BEFORE the oddsmaker. For this reason, I typically win at a much higher rate in the BIGXII conference than I do on teams several hundred miles away. I also look for writeups from people that I respect on their regional action. If you are new to handicapping try putting less on teams that could have problems that you dont know about, and more on teams that you read about every day in the paper.
For the NFL pay particular attention to avg yards per rush for, and avg yards per rush against (defense). A team that can run the ball and stop the run often controls time of possession, and the game itself. There are many other things to look at, and it's hard to explain further strategy without an actual matchup to illustrate, but those two things are considered very important to a lot of people that show profit.
Another NFL angle to look at sounds very simple, but year after year it makes me a LOT of money. Just pick the winner of the game. 84% of the time the team that wins the game covers the spread. What does that mean and how can it possibly help? Well, first do your homework and spend a good deal of time reviewing boxscores, rushing yards, defensive stats, and special teams. After that, in many instances you can come to a solid conclusion about who you think will WIN the game. If you think a team favored by 7.5 points will win the game straight up, dont take the underdog simply because you think the favorite will win by exactly 7. If you think a 6.5 point underdog has a really good chance of winning the game USE the MONEYLINE. On almost all NFL dogs that I wager on I put AT LEAST 30% of my wager on the moneyline, and this almost doubles my profit each year. For example, I typically wager 1.5% of my bankroll on an NFL game. If I take an underdog, I usually put 1% on the +6.5 points and .5% on the moneyline of +300 because 84% of the time if the underdog covers the spread, they WIN THE GAME. If the dog loses by 3 in this case you still make good money. Keep track of your plays, and see how this does for you personally over time- that is the only thing that really matters. Also keep in mind that the NFL has achieved remarkable parity when compared to other US sports, and appx 60% of NFL DOGS covered last year, WOOF!! and best of luck.