If it's your first play maybe you should choose the easy difficulty because this game can be hard sometimes.
Let your grims take damages for you, with "SHIFT + right clic" always place them in front of you when you walk.
There is very often foes who ignore your grims and try to kill you, so use the spell of stunning LASER WAVE, later when you unlock it use VACUMM VORTEX in combination with a MEGA BALL spamming, you can slay groups of foes almost without the help of your summoned grims.
When you fight keep running around of your grims (or not too far), because if you walk too much you can encounter an other group of foes.

Often you can't go back on a map, so always check the whole area before to follow the objective (the green arrow).
Enter every area you can, if you see a yellow circle go on it. If the area is to difficult, come back later. Check before to follow objective.
On every map always check the borders, otherwise you will miss somes spell scrolls or chests.

You can't go back to Grove Valley, so open all the chests while you can (especially the chest in your house at the upper floor).
In the Power Plant the combination to shut down the power is: from bottom to top, a 3 green buttons line, then a 3 red buttons line.
Chapter 8 - Merklyn's prisoner, lot of thing to not miss, so take a save slot.
Punk Temple (Necromancy temple), don't bother you with the guardian ask, slay all the foe.

Find all the chests, it's boxes with purple and blue lights than you can open if you attack them with magic or grims. I won't make a guide with screenshots because there are at least 100 of them. There are areas where you can't go back later so search them methodically before to make the objective. I opened the last chest inside Virtual Bridge (Chapter 10).

Decodify all the floppy disks. Pay attention to the strange four-screens computers, later you will have to put floppy disk inside them.

• Unmissable, at Rocubik house.
  
• Mud Town, north east, close of the enter of the next area.
  
• Wrecklands, south.
  
• Virtual temple (Fulgomancy temple) , Wrecklands south east
  
• Power plant, foreman office
  
• Wastlands, north east
  
• Western Forest, if you walk south to north it's in middle of second red walk among the three.
  
• Camp Miller, north just right of the arcade game.
  
• Necromancy temple (Punk Temple) at Mace's Camp, south east. Inside take middle path and follow until the end.
  
• Mace camp, north west
  
• Techno Rangers headquarters Chapter 10, in the big room who look like a data center, take south east door because if you meet Leoric you can't go back.

Pass the exam, with the best note. At the beginning before you meet Merklyn, you must pass the turrets without you get hurt and finish the target shooting with good efficiency.

Get 100 hits at the minigame. The arcade game is located at Camp Miller, north. You have to spam left clicks to reach the score of 100.

Win the Tourney. Grim Tourney Arena (Camp Miller, north west), come back later to fight again, this time against a punk.

Try the multiplayer mode. In-game summon a grim and control it with a gamepad (press Start, at least xbox 360 controller supported). You can find the co-op mode key mapping in the in-game option.

• MUD FIELD - Vegemancy level 1 - Western Forest
  
• PHOENIX BLUR - Sanctumancy level 1 - Wastelands (First desert map), south east
  
• REPELLENT - Sanctumancy level 2 - Power Plant, room with the colored power bars for shutdown the power.
  
• GRAY SKULL - Necromancy level 1 - Beat Hogan at end of chapter 3.
  
• WIND FIST - Vegemancy level 2 - Mud Town, south west in the cimetery.
  
• REGENERATION TOTEM - Sanctumancy level 4 - Got in the first temple (Desert Temple) after unlock of the Sanctumancy magic color.
  
• ELECTRO-STORM - Fulgomancy level 2 - Win against the soldier in Grim Tourney arena.
  
• HOLOGRAM - Fulgomancy level 3 - Virtual Bridge, first time when you go to Duncan City.
  
• PINBALL - Fulgomancy level 1 - Duncan City (mecha hangar).
  
• DEAD-TONATOR - Necromancy level 2 - After killing the necromancer.
  
• VACUUM VORTEX - Necromancy level 3 - At the begining of the chapter 8, when the timer run and you try to retrieve Fum. You have to make several tries because you have to search every rooms on the map to be sure to also find the chests. You can't go back later.
  
• MEGA BALL - Neonmancy level 4 - Wrecklands, at the south of the enter to Mud Town.
  
• SLOWNESS TOTEM - Fulgomancy level 4 - Fulgomancy temple (Virtual Temple) , Wrecklands South west.
  
• EARTHQUAKE TOTEM - Vegemancy level 4 - Vegemency temple (Forest Temple), talk to the guardian at the far end of the level.
  
• ASTRO HEALING - Sanctumancy level 3 - Camp Miller chapter 9.
  
• HUNT TRAP - Vegemancy level 3 - Mace's Camp, just to the right outside the walls.
  
• MANA TOTEM - Necromancy level 4 - Necromancy temple (Punk temple) at Mace's Camp, south east. Finish the whole temple. Don't bother you with the guardian ask, slay all the foe.

• (Desert temple) SANCTUMANCY temple at Wastelands, south west.
  
• (Forest Temple) VEGEMANCY temple is located at western forest, south.
  
• (Virtual Temple) FULGOMANCY temple at Wrecklands, south west.
  
• (Punk Temple) NECROMANCY temple at Mace's Camp, south east.

My advice, just fight them to unlock the commons informations. After, there is often the "Other info" missing, it's related to your game history progression. So follow the story.

But with some grims you need to make the proper actions to unlock them:

• GARGHOUL: Cast healing spells on them.
  
• ROCKENSTEADY: On the Western Forest map there is a glade with a alone ROCKENSTEADY, don't use your grims but run around the tree in the middle to make the ROCKENSTEADY charge you. And for the "Other info", I guess it unlocks by game progression after finishing of the Vegemancy temple.
  
• REFLEXTOISE: Cast spells on them. If you are stuck, take you time to kill one (do it slow). And for the "Other info", I guess it unlocks by game progression.
  
• FALKEN: Cast MUD FIELD on them.
  
• ANUBEAST: Cast electicity on them (ELECTRO-STORM).
  
• HUSK: Make them fall in a HUNT TRAP.
  
• DESTROYER: "Other info" unlocked after a scene inside mecha hangar (Duncan City, Chapter 10). Do it when you can because you can't go back.

You can find some DESTROYERs and TURBO-LIONs to fight when you return to Power Plant.
You can find some PUNK PANTHERs to fight at Punk Temple (Necromancy temple at Mace's Camp, south east).
You can find some REFLEXTOISEs to fight at Wrecklands, south.