Get in place a healthy diet and exercise system--something like Weight Watchers, SugarBusters, or South Beach--and let nature take care of itself when it comes to losing weight before you get pregnant. I'm sure there are other diets that are OK, but I know that those three are very well-balanced, and you can continue the same eating principles during your pregnancy (I'm especially fond of SugarBusters & South Beach, which emphasize whole grain products much more than Weight Watchers seems to). Nutrition prior to pregnancy plays a large part in having a good pregnancy, so if you look at it as a way to get into the habit of eating well, and focus less on losing weight, you'll relieve yourself of a lot of stress, & probably lose weight at the same time.
Being overweight while you're pregnant does seem to put you at a higher risk than some things, but the research is far from conclusive. There are plenty of overweight women who have perfectly healthy pregnancies, but you have to be picky with your care provider. Before you go about trying to get pregnant is probably also a good time to start your research into pregnancy, which it sounds like you're doing. And check out alternate sources as well as mainstream ones. (Which is to say, pick up
Mothering as well as
Parents.
)
As far as the showing issue...There is a thread with some belly shots
right here and another
here. When/whether/how well you show depends on a lot of factors, not just weight. I am so large right now it is hugely obvious to me that I'm pregnant, even in clothes, but to date not one person has noticed without being told, and I'm 7 1/2 months pregnant. No one ever seems to notice with me, even though it's always obvious to my husband & I. It seems that people see what they expect to see, and when they look at me they expect to see a fat woman, not a pregnant woman. (Though I'm not certain what else would cause a woman to gain 20 pounds all in her stomach.)
If it is any consolation, for every woman bemoaning her lack of a cute pregnant belly there is another one complaining because she's already so huge total strangers think she's overdue. And there is some subversive pleasure in springing a newborn on acquaintainces who never noticed you were expecting.
Some getting PG questions/concerns
I want people to know im pregnant! I want to be proud. But Im afraid at my weight no one will beable to tell until my last month or so 
Has anyone around my size been pregnant and do you have pics? even ones you could send just me. 
Is there any thing healthy I can do to lose some weight and still be healthy when I do finally concieve? Or can I work really hard before getting pregnant and lose as much weight as possible and still be healthy??
) and start exercising regularly, or atleast getting up off the couch every once and a while 
I guess i really shouldnt worry about being asked if Im pregnant by strangers... I get that already and im not even pregnant yet 
if they're not!! I like GBMM's idea of surprising people by suddenly having a baby 