Installation

I always install all apps (except for maybe matching gifts) because there are too many linked things that could go wrong if they are not all installed.

Other Apps that work with NPSP

Setup

See Accounts for setting up your Accounts object.

See Contacts for setting up your Contacts object. Optionally rename Contacts to be Individuals depending on the balance of individuals in your data mix.

Organisations and Contacts

https://powerofus.force.com/articles/Resource/NPSP-What-is-an-Account-Model

I prefer the 1x1 account Model.

Advantages

Clearer separation of donation money
No worry about how many individuals are linked to the bucket account.

Disadvantages

two records for each Individual contact
Can't use Contact Merge (but the Demand Tools app handles that).

Affiliations

Affiliations works well and is a great feature of NPSP although the new feature in Salesforce of one contact to many accounts also works well.

Households

Households with the NPSP 3 is much easier to use.

Matching Gifts

Why does Matching Gifts install a Donation object when NPSP renames Opps to Donations?

Leads

Opportunities / Donations

Depending on the type of money you receive, think about renaming Opportunities to Donations or even Money or Payments.

Entering donations - read http://nickhbailey.wordpress.com/2012/04/09/how-do-i-enter-this-donation-a-primer-for-npsp-users/ especially the picture. (Quotes below from this article).

Contact Roles

The person making the donation is added as the Contact Role.

"The Primary Contact Role determines which Contact will get this Donation rolled up to their giving totals. This would be desired in almost every individual giver scenario."

Remember:

Organisations don't make donations, people do, on behalf of organisations. There is always a person responsible for the payment.

Think about using Opportunity Primary Contact validation to ensure all Opps have a Primary Contact.

Soft Credits

Understand Soft Credits!

Rollups

Rollup Setting is in the Household Settings tab.

http://training.handsonconnect.org/m/6676/l/75076-how-do-rollups-work-in-the-npsp

This is a very good answer on Stack Exchange http://salesforce.stackexchange.com/questions/8392/donation-roll-ups-are-not-working-on-contact-and-household

Campaigns