Merging 2 pictures fluedly

Probably this is a very n00bish question but I can't figure it out. I tried to search the web for it but I'm dutch and don't know the correct word for the action I want te perform, that is way is limits my search results. I also didn't have any training in photoshop whatsoever which means I do everything by using tutorials and figure things out myself. The thing I want to do is make some wallpapers for my BF2 clan. For example, I made the following wallpapers already:

http://members.home.nl/hvandeplas/Clan/BoB2%20copy.jpg

But at this point I would like to make a wallpapers in which different screenshots are merged neatly, like here for example:

http://www.totalbf2.com/images/wallpaper/bf2_04_800.jpg

I'm using Photoshop 7 and already tried gradients and tried to find some stitch function but both without much succes. I'm a real n00b in this, so pls explain things as simple as possible. Thx anyway for your reply!!!!

I may be still a noob but why don't you just bring in renders and put them togather with a different background. And if you want to make it with different scenes then merge different backgrounds with small scenes and blur them togather.

Masking would help with that alot... (i think) i haven't done a whole lot, but i do know is that this is one way to possibly do it. Bring one of the images over hit the quick mask button and paint black were you want the image to fade out, make sure you do it in a light opacity brush though. yet again i could be completely wrong but give it a try see if it helps.

masking and erasing are what your trrying to do.
look up tutorials on masking.

Eraser + Polygonal Lasso + feather + brushes.

And then dodge/burn as required + gradient overlays 'n' shiz.

I tried to combine some things you guys advised but couldn't apply all things properly. I want to combine these two images:

http://members.home.nl/hvandeplas/Cl...rplane%202.jpg

http://members.home.nl/hvandeplas/Clan/US%20Tanks.jpg

I used some overlay with gradient on the airplane image. But in the final result I can't really see anything from the gradient since I used a large eraser brush (100) with 100% opacity and 50% flow to let both images "flow" into each other and delete the visible edges. I'm not really satified with the final result (don't mind the text because I added that to get an impression) because there must be a better way to get rid of the edges and let them smoothly integrate with the other one. If you feel like trying, be my guest and pls tell me how you did. This is my final result:

http://members.home.nl/hvandeplas/Cl...ry2%20copy.jpg