Hold down the shift key then click the item; this negates the need to simply drag items to/from slots in the inventory or hotbar and vice-versa. ;)
well there is a mod for that or you can download too many items and there is a botton on the left where you can save your inventory so if you die you will have your stuff by clicking that button
You don't have an intrevory in minecraft, but we do have an inventory.
press e to access your inventory, then drag your items for the lower bar to your inventory
Inv Edit basically allows you to spawn in items from your inventory.
You will lose all the items in your inventory and your experience and respawn.
Once you have installed Too Many Items, when you bring your inventory up, you can choose from a list of blocks/items that appears by the side and click them into your inventory.
Minecraft only lets you stack most items to 64, you cant place 64 different item in your inventory only 36 stacks of items. (if that's what you meant)just collect 64 of the item. not all items stack to 64 unless your using a mod that lets you.
From your monsters room, open your inventory by clicking on the chest icon, and then drag items from your room towards the bar at the bottom of the screen and release them. These items will then go to your inventory.
Open the chest and then you will be able to drag items into the chest, in which they will then be removed from your inventory.
If you have items in your inventory that you wish to put in your room then open your inventory, by clicking on the chest icon, and drag the items from your chest towards your room and release the item where you wish it to be placed.
You can't really cheat, but there are some mods (specifically, Single Player Commands and Too Many Items) that let you give yourself items. There are also inventory editors that let you edit your inventory and give yourself items.
Press E to bring up your inventory screen, your character has four armour slots, drag armour items from your inventory into the slots.