When creating printed media for a corporation/legal entity, what exactly should I consider when using my own, personally created and designed, fonts?
Clarification: We are designers, for real answers you should ask a lawyer.
First thing I would consider is: Were you paid by the company to design this typeface, or did you have it before you used it for the project?
If you were paid to do it, then the type's right probably belongs to the company, and not to you (depends on your contract). You can most likely display it in your portfolio, but you can't use it or sell it. In this case, the company would choose what sort of license they want to give the font.
If you designed the typeface on your own time, then you are the owner and you can decide the License you prefer. You can give the font to the company, either for free under no license, or under a Creative Commons license with commercial use allowed. You can also sell the font to them, in that case it would be release as copyrighted.
Some more information:
Typically a computer font may be regarded as a program that converts a machine-readable piece of text into an image thereof. While it is possible to apply almost any kind of license to a font, and some licenses might give a font owner a partial copyright interest in the images produced thereby, a more common form of licensing would state--as would copyright law in the absence of a license--that images produced using the font "program" are the property of the people who used the program to create them, and are in no way the property of the people who created the program itself.
As such, unless the fonts you created are owned by some other entity which would bind even you to an unusually-tight license, you would be free to use the font in producing a client's logo provided that you did not give the client a means of converting other texts to images using the same font.
On the other hand, many companies find considerable value in having a complete font whose appearance matches the text in their logo. For example, if a beverage company named "Total" had a logo with the word "Total" in a particular font, it may wish to produce adds which say "Total Perfection" or "Total Amazement" or other such things. Thus, it may be helpful to license the font as a font separate from the logo; the optimal way of licensing that would depend upon whether the font is owned by you or your employer, and also potentially on whether the value the client would receive for exclusivity would exceed the value you could get by using or licensing the font elsewhere.
I write this answer to add to and clarify the other answers, so I will in parts be repeating stuff.
Most importantly, you should know whether you already gave exclusive rights of your font to somebody else or transferred the copyright or similar, which typically happens if you create that font while working for somebody. In this case, what you are allowed to do strongly depends on the respective contracts and you need to check them. Even then, you are likely allowed to distribute and sell something that you created using that font, which may suffice for your case (see below).
Otherwise (and if you are the sole creator), the font is your’s and you can do with it almost whatever you like – which I assume to be the case in all of the following.
Note however that you might be working under some contract right now that transfers your rights on stuff you create now to your employer (or similar). In this case, you should make clear that you did not create that font for them. To this purpose it should suffice if you published that font or something using that font prior to your current work.
The main thing you need to consider is that the company you are working for wants all the rights to the font that it needs to have:
If you are creating printed material only and the font never needs to be installed on another computer, they do not need any special rights on the font at all – they only need some rights on what you created using that font, which they have likely secured anyway, given that you are working for them.
If the company needs to create material using that font itself (e.g., to create ads with it or to use it as part of its corporate identity) or they even want to use it as a webfont, you will need to grant them some rights to do this or, with other words, you need to license the font to them.
You can do so by generally releasing the font under some open license such as the OFL¹, but obviously this would make it difficult for you to make money with that font afterwards. If you do not want this, you need to make an appropriate contract (or license) that allows the company and only the company to use that font as required, which is somewhat complicated (in particular for webfonts). However, big font vendors have experience with selling fonts under such conditions and you can take a look at their licenses for inspiration.
Note that the above does not consider what you get for that font from the company. Some of your pay may be implicitly dedicated for you buying fonts and you cash that money for yourself, or the company expects to buy a new font anyway, which they now buy from you instead of a third party.
¹ Note that fonts licenses require some special consideration as you need to distinguish between the rights granted for the font itself and something created using that font. Therefore “standard licenses” such as the CC licenses or the GPL are usally not a good choice for fonts (there is a variant of the GSL for fonts though).