Inserting Special Characters
On the PC there is a built-in application called Character Map where you can find and copy special characters to the clipboard and then paste them into a document. On the Mac it is done more elegantly. In applications that edit text go to the Edit menu and select Special Characters… (or Command-Option-T). This will bring up the Characters window.
To narrow down the choices you can select a view (e.g. Roman) and then within that view in the left panel are some view-dependent categories. To get accented letters, for example, choose Accented Latin. The combination of views and categories make it much easier to find characters of interest than selecting by font as is required in Windows.
Once you have found the character you are looking for, select it and then click on Insert and it will be inserted into your document at the cursor.
If you know that you will want to use the character again you can add it to your Favorites using the action pull down menu in the lower left of the window. Then you can get to the character quickly by selecting the Favorites tab.