In French, happy birthday is written as 'joyeux anniversaire!' The other ways to say/write/ wish a happy birthday to some one is 'Heureux anniversaire!' or 'Bon anniversaire!' You can also use 'joyeux et heurex anniversaire,' if you like.
In case you are writing to wish someone in advance, use 'Joyeux et heureux anniversaire à l'avance.' You can use a search engine and write the keywords ''souhaits anniversaire" to find innovative ideas and sites in French for birthday. Nowadays you can even send e-cards and text messages to the birthday boy or girl in French. However nothing beats the personal touch conveyed by a greeting card in which you pen your wishes.
Dailyfrenchpod is a very good source to learn french online. You can download free podcast, which is quite handy and easy to learn.
In case you are writing to wish someone in advance, use 'Joyeux et heureux anniversaire à l'avance.' You can use a search engine and write the keywords ''souhaits anniversaire" to find innovative ideas and sites in French for birthday. Nowadays you can even send e-cards and text messages to the birthday boy or girl in French. However nothing beats the personal touch conveyed by a greeting card in which you pen your wishes.
Dailyfrenchpod is a very good source to learn french online. You can download free podcast, which is quite handy and easy to learn.