Method #1 -- The Spelling Way
Just as you learnt your spellings many years ago, you can use the "look, say, cover, write, check" method for dates as well.
Make a list of a few, related dates of events you need to know, say 5-10 at a time. Write them down in a list, look at them and read them out loud to yourself. Cover the list with your hand, a book, etc, and try to write out the list again. Check how well you've done; see if you've missed any out.
Repeat as necessary, making the list longer and longer, until you can remember all the dates in the list you need to know.
Method #2 -- The Flashcards
Buy yourself a selection of flashcards -- coloured, if you wish -- and write a year/date on one side, and the events that happened upon that date on the other.
First, you can try things the easy way. Spread out all the cards, year side upwards, and try to guess everything that happened on that particular year. If you get them right, put them in one pile; if wrong, in another. When you have run out of cards, re-shuffle the ones you got wrong and repeat, until they are all in the "right" pile.
Then you can make things more tricky, by trying to recall the date from the event. You can also give these to a friend/family member and ask them to test you.
Method #3 -- The Krammers
This is just like Flashcards, but with the revision tool "Krammers". They are little strips of card all attached to a keyring.
Write the date on one side, and the event on the other, and you can use them just like the flashcards. These have the added bonuses of being able to fit in a pocket, of be attached to the edge of a bag or pencilcase.
Method #4 -- The Doodles
If you like drawing, or think of yourself as a "visual" learner, this one may be the best method for you.
Take a blank piece of paper and write the date you need to know in big letters all across the top. Now take up the rest of the space doodling or drawing the events of that date all across the page.
This method is great if you like to hang your revision notes on your bedroom wall or around the house, as they'll be really eye-catching!
Method #5 -- The Mnemonics
Probably the easiest one, as it requires no tools or even a pencil -- just an imagination!
Make up mnemonics to remember key dates and events. This can be anything from an acronym to a rhyme to help you remember the dates you need to. For example:
In fourteen hundred ninety-two, Columbus sailed the ocean blue.