Here's the command you need:
/give @p diamond_sword 1 0 {Unbreakable:1,display:{Name:<Sword Name>,Lore:["<First line>","<Second line>","<Third Line>","<Fourth line, and you can add more of these>"]},ench:[{id:16,lvl:100000}]}
-'/give' is the command being executed
-'@p' is the player or entity being effected by this command
-'diamond_sword' is the item being given
-'1 0' are the amount of items, then the durability
-'{' opening to the list of tags to be added
-'Unbreakable:1' means the sword is... well, unbreakable. You can remove this if you want
-'display:' is the opening to controlling the name, and lore (lore is just the little item description)
-'Name:' sets the name of the item
-'Lore:[" "," "," "," "]' the description, note that it must all be inside of the specified areas.
-'ench:[' this is where you put any and all enchantments to the item
-'{id:16,lvl:100000}' the ID for sharpness is 16, so this is a sword with sharpness 100,000
-'}' end of tags. Very important for any of the tags to work.
I hope this helps.
