I am uncertain what to use as a light source to expose the photoresis for PCB making
As others note, light required may vary with resist type, but many (or most) use UV and a germicidal UV lamp is usually very adequate (as is longer sunlight exposure). 

Germicidal lamps are usually fluorescent like tubes but with no phosphor so the UV is not converted to visible light. As Spehro says, they will happily damage your eyes (my wife spent several days with BOTH eyes bandaged after UV from such a tube was diffracted into an unexpected location. (Not her fault.))
BUT I have used them often (for resist exposure and for product testing) with due care and no problems. A quick occasional glance is usually acceptable BUT do read up on your tube ratings and exposure times and distances.

You want reasonably even exposure so for very large boards you may need multiple tubes. A folded CFL type lamp gives a broader light sources in a single package.
Right hand two tubes here are UV. ( from here )



Many examples of germicidal lamps are available here 

Genuine shortwavelength UV LEDs are becoming more common but are usually costly per UV output compared to 'fluorescent" type devices.
Allegedly "UV" LEDS at lower cost are available but are almost always unsuitable as they are either very "near UV" so lower quanta of energy in each photon or really just deep blue with about no UV. 

What country are you in?
You can probably get suitable lamps on ebay or selected retail outlets. 

Many ebay germicidal lamps here - most but not all are genuinely short wavelength UV. 

This is an example of an unsuitable lamp on sale on ebay and sourced from Hong Kong. While they claim it to be a germicidal lamp it is a longer wavelength "black light" lamp.  The dark glass and purple-blue output show it is NOT a short wavelength lamp (or largely not).



The good oil.  Typical appearance.
Clear glass - a major indicator.
Some visible blue/purple. Visible component Low for wattage. 

Do not stare at lamp with remaining good eye !   



Safety:

I do not wish to discourage people with safety aspects or overemphasise the risk. I'm less careful than some people in many areas (ie  I'm an engineer) but stay aware of the risk factors. I have glanced at an eg 15 Watt germicidal UV tube at distances of maybe 500-1000 mm on numerous occasions but only for a brief moment and perhaps a few times on most uses. I have NEVER had any eye problems as a result.
But I have had mild "snow blindness" from UV exposure while skiing (long ago) so know what the results are like.

I am not a doctor / YMMV / All care but YOUR responsibility:

Instant blindness will NOT occur with lamps normally encountered - over exposure will initially lead to sore eyes, then inflammation and VERY sore eyes. This is the same as 'snow blindness' experienced when skiing at altitude for excessively long periods without goggles. I am assured by medical experts that exposure to levels that make your eyes unusable for several days but not grossly worse than that  (as in my wife's case) are NOT a threat to the retina, as one may expect them to be. I have reasons to doubt this opinion, but too complex/detailed/irrelevant for this forum. 

Requirement for sore eyes - Guesstimate only: probably a few 10's of seconds in a day at 500 mm+ with tubes of under 30 Watts. I'd never get anywhere near that level.