You can look up water and sewer rates by town, (typically listed by hundred cubic feet so make sure you're converting to the right unit) and calculate based on some average use per bedroom, anywhere from 20-100 gal per bedroom per day depending on how conservative you want to be.
Maintenance I usually have set to 1 month of rent per year, i.e. 8.33%. This obviously varies widely by building but for the most part it seems to end up somewhere in that range over the long term. Capex I typically set at $125 per unit per month, I would not go any lower than this, and if you're looking to buy in the city I'd definitely go higher because everything costs more in the city. Landscaping depends on size of the lot, but I figure fall and spring cleanups, and that the lawn is being cut every other week from April thru October, again cost per cut varies widely by lot size, where the property is located, etc. so you just kind of have to know what that costs. Same for snow removal, varies based on a lot of factors but I know about what it costs where my properties are located. Also make sure you're having common walkways and stairs cleared of snow, typically you have to pay extra for this. Seasonal expenses like landscaping and snow removal just need to be capitalized monthly for analysis purposes, simple enough calculation there.
Management anywhere from 6-10% depending on the area and level of service you're after. Also make sure you include tenant placement fees if they're not typically paid by the tenant in your market. Boston and surrounding areas typically the tenant pays the fee, further out you go this is usually paid by the landlord. This can be calculated based on an assumed average length of tenancy and similar to seasonal expenses, capitalize it monthly for analysis purposes.
*Edit - I didn't mention vacancy but of course you need to include that as well. Market dependent. Also things like common area electric, other misc. costs I include I did not mention but there are costs over and above what has been summarized above.