There is so much info and so many different ways to go about it Catrionalee. Heaps of good tips in this thread and previous one. Or you can google (gender selection). There are online companies who provide complete packages or there things to try for yourself. Just depends how you want to go about it.
Heres what I am doing to get a package of bugs and snails and puppy dogs tails (IS that really what little boys are made of???) Anyway... I already have two lots of sugar and spice and everything nice.
Charting cycle to pinpoint ovulation and then
DTD as close to that day as possible
Abstain for about 4 days previous to Ovulation
Taking supplements to increase sodium and potassium
Take ural powder daily to alkalise my system
Follow "boy diet" (kind of) for 8 weeks (I was very acidic to begin with)
Avoid eggs and milk and COFFEE

Use
BD position with deepest penetration
Get
DH to drink coke or coffee 1 hour before
BD
Get
DH into boxers instead of briefs as much as possible
Get
DH to take Zinc supplement to improve quality of swimmers
Considering using the "bi-carb finger" but still undecided
And if all that doesn't bring me the little blue bundle I am hoping for... well then, I guess it just wasn't meant to be. Three is definately my limit.