If you want some colors to pop and be more vivid than others in the same photo, then chose paintbrush, and then select 'saturation' mode (at the top, where it likely says 'normal'). Then, just paint over the parts that you want to be vivid. Or, depending on which photoshop you use, you can simply select 'vibrance' under adjuctments, and up the saturation.

It looks like a gaussian blur in the background too. The focus wouldn't blur the background out that well on the camera. In this case, duplicate the layer twice, discard the background layer, and apply the gaussian blur to the lower layer. Then using the eraser tool, on the top layer, erase the parts that you want to be blurry, but be carefull to avoid any edges of the part of the image that you want to remain sharp.

The bottom image looks like the levels were played with. This option would be under 'adjustments', or in the same place that you'd find the vibrance. slide the gray marker untill you get that whitish filter the way you want it. Once you have the right amount of white, duplicate the image, right-click the top layer, and select 'blending options'. Double-click 'inner shadow' to view the defaults, select the angle of your shadow, turn the distance and size right up, and play around with the contour untill the shadow is where you want it.

Hope this helps! Have fun! If you have any other questions, please ask ;)

I use CS4 but am also familiar with older versions of photoshop if you need more specific instructions

The top photo features some really rich colors while the bottom one a more desaturated pallette.

Top One:

A great way to make colors really pop is to duplicate the image layer and in the top layer set the transparency to 'soft light'. Cool huh? Now, alternate increasing the saturation in the top layer and also the % of transparency to soften the effects. Also try sharpening and blurring the top-most layer for some interesting effects. Use the sponge tool in desaturate mode to soften the impact of the background photos.  (show us what you come up with)

 Bottom One:

For the vingetting, use the dropper tool to sample a dark yet prominent color from the photo, double click on the color square to edit the color and darken it until it is only 3-4 shades from black if it isn't already. Now fill a new layer with your new color and set the transparency to 'Multiply' or 'Overlay' and begin eracing it with a large blurry brush till you get the vingette effect you desire. Keep playing with it, you'll find something you like.

As far as the coloration, I would begin the same way as the first photo, but play around rather with desaturation even creating more layers like it and earacing and changing the % of transparency in the layers. Ultimately your color control is going to come from a levels adustment, I suggest a levels adjustment layer for this. Be sure to not just play around with the color levels in the main pallette, but play around with individual channels by using the dropdown at the top of the Levels dialog to choose between 'Red' 'Green' 'Blue' 'Black' and CMYK colors too.

Hope that helps.

-Aaron 

Not sure about any particular process on the top photo, but on the bottom, if there were a regular shot that you started out with and then made a copy of the layer to apply effects to, I might use that route. I would add a blue hue layer or color layer and just deleted a feathered circle from the middle of that layer so that it really colorizes/burns the outer edges like above.  On the people part, there are a few different ways, but I would start by making a white overlay later, but cutting a mask in that white later in the shape of the people so that you don't blow them out on color.

It makes sense to me, but I am not sure how you might approach it in PhotoShop.  Everyone's style in photoshop is like a fingerprint. Hope I've helped!