Ako sis, I was a working student din back when I was in UP Manila. It was hard and I was doing thesis pa at that time. But I had no choice kasi pinapaaral ko kasi sarili ko, buti na lang mababa lang tuition sa UP. I started when I was in 2nd year as student assistant. Nakaraos naman until 3rd year even I was earning 25/hour lang nung. But came 4th year, I applied in a coffee shop and got in. Of course, mas mataas kesa sa ineearn ko nung SA. So this is one of your options, apart from odesk which I think is a good idea, since hawak mo yung oras mo. I had a great time while working in Coffee Bean, stayed there for 7-8 mos. Just had to resign kasi a month na lang, gagraduate na ako, and I needed to finalize my thesis.
With workload, minimum of 4 hours and maximum of 7 hours. Usually 4 hours ako when I had classes but on weekends, ayun 7 hours talaga. Managers are understanding naman when it comes to working students eh.