Fax Help Needed

Does anyone have good tips and advice for faxing from a Mac using Tiger (10.4.8). I followed all the steps given in help, FAX PDF, etc. and the modem status boxes came up, but they just didn't go. Is it a question of patience, does it just need to keep trying and holding, or do I need to space the numbers or something?

Also, does it make any difference whether I use the internal dial-up modem or the USB/ADSL modem to send the fax?

Thanks in advance.