The two ballot initiatives are:

I-77, the "espresso tax", which would impose a 10¢ a cup tax on all espresso beverages sold to pay for childcare programs. Vote NO. Although it has been sold as a way to fund early education for low-income children, the text of the initiative makes clear that only a fraction of the funds would be earmarked to benefit low-income families, most of the money would be used to subsidize childcare for other families, including high-earning dual career couples. The burden would be borne mainly by low-margin small business owners, their employees and those who happen to drink espresso beverages instead of other forms of coffee. Indeed, the promoters of the initiative have a largely underreported hidden agenda, which is to raise wages for and to unionize childcare workers. (HINT: if you want to make a service more available to low-income people, do not start by raising the cost of the most significant input). A list of the initiative's financial backers tells the story. 25% of the money for the campaign comes from outside of Seattle (i.e. from folks who won't share in the burden of the tax). 38% of the money comes from the Economic Opportunity Institute, a union funded think tank that is involved in the movement to raise wages for and to unionize childcare workers. Other major contributors include Seattle Education Association, Washington Education Association, King County Labor Council, Washington State AFL-CIO, Washington Federation of Teachers and the Ballot Initiative Strategy Center, a Washington, DC-based union-oriented PAC.
There may well be a case for municipal funding of childcare for low-income families, but taxing only certain beverages to pay for everybody's childcare while simultaneously unionizing daycare workers is a hideous idea and should be soundly rejected.

I-75, which would require the police to make enforcement of marijuana possession laws (for personal adult use) the lowest priority. Vote YES. The police surely have more important things to worry about. Some object to the initiative because it's symbolic and won't have much of a practical impact. So? Others object on the grounds that it's not appropriate for the public to tell the police how to do their jobs. No, it is appropriate for the public and council to both make laws and to set priorities for law enforcement.

Summary: YES on 75, NO on 77