Editing advice

Hi There,
I seriously hope this isn't too stupid a question. I'm fairly new to pp and am loving it. Am using Lightroom 3 and Photoshop Elements 6.
I find that when I take a set of photos (of a baby etc) the set often looks out of sorts because I use different too many colour edits on them.
Is there a general rule of thumb as to what sort of colour edits you should stick to when editing sets? for example just a vintage washed out look and others and one type of black and white (eg a chocolate)? I know a single photo is fine and you can do whatever, but should there be a recurring theme throughout the album?
How many different type of edits would you do in a set?
Does this make sense?!

I see what you mean about mismatching themes. I just created a photo book of my nieces and nephew and I had an assortment different post processed looks to the photos. Somer were black and white, others color, and others in between. I think it blended nicely but I tried not to over do it if you know what I mean. Too much b&w and it becomes boring. Too much over saturation, and it becomes distracting. Find a good mix. You are the artist remember.