You can, in theory, set the swap size to be as large as you like—or at least as large as can fit on your SD card or storage medium. There is no practical limit I'm aware of that you would hit for a Raspberry Pi in terms of swap file size—more powerful computers often have many gigabytes of swap if necessary.
As for suggested values, that depends to some extent on what you'll be doing with the Pi. If you search around you'll hear many different recommendations for swap; usually some multiple of your RAM size. The most common ones I hear are 0.5x your memory, 1x and 2x your memory. That puts you somewhere between 256 MB and 1024 MB.
If you're likely to be doing anything memory intensive (e.g. running a GUI, playing a video, running a web browser, ...) you may want to have a larger amount of swap, but if you're just using the terminal you may need less. It is worth remembering that if you run out of memory and swap space, either processes are terminated or the system crashes.
- there is no practical limit to the amount of swap you can allocate
- using swap is slow and best avoided, but it is usually better to swap than crash your system
- you can configure your swap by editing