I think if you are serious about Internet dating then you need to use more than one site.
I don't mean go and register yourself on every dating site at the same time! That just smacks of desperation. But instead of signing up to one site for a year, sign up to one site for a month....another for month 2, another for month 3.
The reason is quite simple. Your chances are best when you are new. All the other muppets will have signed up for a year and soon only the new people will be interested in you. Existing members will either have already mailed you, or will not mail you because they think "Well something must be wrong if he/she is still on there after x months". Whereas if YOU are new, you are noticed more by everyone on the site. I'm probably not describing it well but hope you get the idea. In fact for some sites I dipped in for a week then left it a bit then came back a month later.
As for your photos, I used to make sure each painted a little picture. So there was one of me at a theme park with a bunch of friends (ie. I have fun and have friends). Another was me driving a racing car (ie. I do exciting things), one just sat in a nice kitchen (ie. look at my kitchen). NB. It doesn't have to be YOUR kitchen, it's all about imagery. One thing I never did was have a photo with a bunch of blokes with beers. All that screams is "I like to drink with the lads!" The opposite is also true. I hated seeing photos of ladies who had wine in every photo or was clubbing. All that says to me is "I like to get drunk a lot and go clubbing". Not what I want in my late thirties.
@JuJusdad. Mate, don't know how old you are. But treat the whole thing like a sales exercise. The only thing is that you are the product! 
So if I were marketing you, your biggest selling point is the fact that you work full time and are the type of man who steps up and is a full time dad rather than one whom has dumped his child along with his ex. Don't underestimate these qualities. Plenty of blokes out there have neither!
Your target "market" would be other single parents. So a good place to look at are sites which specalise for single parents. Datingforparents, mumdatedads & parentsalready spring to mind. Sure you can go gunning for single women with no kids but they're unlikely to understand your world. You could strike gold but the stream of rejection will be harder to take.
Finally your biggest problem is childcare. I think you need to work out who can help you out with that. Do you have other family/parents who can help? Without that you can't get out so you can't get past step 1 anyway.