Simple. Press R1. That will give you any information you've gleaned on the current enemies. You can cycle through your current enemies by pressing R1 or L1. If you don't have anything on them, cast Libra on them, and then press R1. That will do the trick.
It depends a lot on the game. Some games you won't have to do anything, they use the same save file format and use the same directory to store them in. Other games will use the same file format but you'll need to copy them to a different place. Unfortunately some games will use a different save game format and simply aren't compatible the Steam version.
If it's an old game that keeps its save files under the same directory where the game is installed, then generally you can copy the save files to same place relative to where Steam has installed in the game. So if the old game had it's savefile stored in C:\Program Files (x86)\Old Game\SaveFiles you can copy them to C:\Program Files (x86)\steam\steamapps\common\Old Game\SaveFiles and there's a good chance they'll work.
If it's a newer game that stores the save files in a different location than where the game is installed, and if the game doesn't support Steam cloud saves, then you'll probably won't have to do anything. The Steam version of the game should look for the save file in the same place.
If it's a newer game that supports Steam cloud saves then you'll have to copy the save files to the directory where Steam keeps cloud saves. This is C:\Program Files (x86)\steam\userdata\user-id\game-id\remote, where user-id and game-id are numeric id codes for your Steam account and the game respectively. If you're the only one using Steam on your computer than figuring out your user id is easy, it'll be the only subdirectory of the userdata directory. Finding out the game id will probably require looking it up on the Internet.
The hard part is figuring out where the non-Steam version of the game saves it's files. There are numerous locations games developers have chosen to store save files, so you'll need to search for them. Sometimes they'll put them in your "My Documents" folder. Even within that folder there can be lots of different places they can story the files. Places like Game Name, Game Name\savefiles, Publisher Name\Game Name\savefiles or My Games\Publisher Name\Game Name and various other permutations. Other games choose to hide them in one of the application user data directories under C:\User\User Name\AppData. These directories, and their subdirectories are normally hidden so you may need to turn on the option that lets you see hidden files in Explorer.
If you manage to find them then there's a decent chance if you copy them to the appropriate Steam cloud save subdirectory you'll be able to use them in the Steam version game.
Finally any game that uses Games for Windows Live likely encrypts its savefiles as crude method of copy protection. Unless the developers provide a means to decrypt the savefiles and use them with Steam there's nothing you can use these save files with the Steam version of the game.
Be careful with any solution that involves copying your save files. Don't move them, just copy them. You don't want to delete your old save files in case something goes wrong.
Best Answer
I'm not familiar with the Xbox saving system, but I once read about exporting Skyrim stuff between 360 and PC.
Here's the reddit thread: http://www.reddit.com/r/skyrim/comments/mfgrp/psa_you_can_transfer_skyrim_savegame_files_from/
A search about FFXIII save files yields this: http://www.reddit.com/r/FinalFantasy/comments/2jew4y/where_are_ffxiii_pc_save_files/ and this: (see comment for link, not enough rep)
So I'm positive you should only have to retrieve the "ff13-00.dat" file from the Xbox using that "Modio" program and place it in C:\Users\[username]\AppData\Local\SquareEnix\FinalFantasyXIII\save
For Modio usage, (taken from the first link): Copy the x360 save file from your Xbox to your 360 Formatted USB Drive. Open with Modio. Click open from device locate the save file and open it. Click the file contents tab. Extract ff13-00.dat.