Hi, James.
Each of your talents requires a different approach to work in Israel.
As a graphic designer or computer technician, you would apply directly to companies in Israel. They will look at your academic qualifications and your experience, and decide whether to offer you a job. If they did, then you could apply for a work visa in Israel. In general you would have to pay your own transport to Israel after you received the visa. The competition in these areas is very high.
It is practically impossible for a foreigner to get a paid job in archaeology in Israel.
For farm work, you would check with the Malawi government about the bilateral agreement between Israel and Malawi concerning work in Israel. At the same time, you would write an email to the Department of Agriculture and Rural Development in Israel asking about this possibility. The email is moked.sherut@moag.gov.il
For Caregiving, you would apply to any (or several) of the many agencies here in Israel that arranges caregiving positions for foreigners. An overview of the paperwork that you will need to assemble before applying is given here: Once you get your first job, and hence a visa, there are many caregiving positions  are offered for those who are already in Israel and have a visa. So it is worth it to get that first job at a lower salary, and then jump to better positions once you have the visa and are in Israel. You can look in the Internet for the addresses of such agencies.
The cost of living in Israel differs from place to place. In general the cost of living is quite high; if you get a farm job, you will often be given room and board as part of your contract. (I know someone from Thailand who worked for several years on a farm here, and was quite happy about it.) Tel Aviv is one of the most expensive cities in the world. The currency here is in shekels, but I will give you some approximate prices in dollar equivalents. The rent for a small apartment for a single person in a smaller city or town will be at least US$400-$500 per month, and then you must pay a tax and utilities. Food is generally also expensive -- potatoes presently cost about $1.50 per kilo, milk costs about $1.50 per liter, etc.... generally you would need to spend at least #1000 per month, without rent. In other words, you would probably need at least $1700 per month to live in most places here.
That is an overview. IÂ would be glad to answer more specific questions if you have them.
Cheers, David