Ruby on Rails is a powerful web application framework designed for rapid development and simplicity. As a beginner, understanding the core concepts is crucial for effectively utilizing its capabilities. Rails follows the model-view-controller (MVC) architecture, which separates your application into three interconnected components: the model handles data, the view presents the information to users, and the controller manages the interaction between them. This structure not only organizes your code but also promotes modularity, making it easier to maintain and extend your applications as they grow.

To get started with Ruby on Rails, you first need to install Ruby, followed by Rails itself. Here's a simple guide to help you set up your environment:

1. Install Ruby: Use a version manager like rbenv or RVM to easily manage Ruby versions.
2. Install Rails: After setting up Ruby, run the command gem install rails to install the latest version of Rails.
3. Create a New Application: Use rails new app_name to create a new Rails application and start building your web project.

As you embark on your Rails journey, remember to leverage the extensive documentation and community resources that are available. This support can be invaluable as you learn and troubleshoot your way through development.

When it comes to enhancing your Rails applications, leveraging the right gems can make a significant difference in development speed and functionality. Here are the top 10 gems that every Rails developer should consider:

1. Devise: A flexible authentication solution for Rails, allowing you to easily manage user accounts and sessions.
2. Pundit: This gem provides a simple and extendable way to implement authorization, enabling you to control access to different resources in your application.
3. ActiveAdmin: A framework for creating elegant backends for your application, providing a customizable interface for managing data.
4. Sidekiq: A background processing tool that allows you to run jobs asynchronously, improving the performance of your application.
5. Rspec-rails: Essential for writing tests in Rails applications, Rspec allows you to ensure your application behaves as expected.

Continuing with our list, here are five more gems to elevate your Rails applications:

6. Cloudinary: Simplifies image management in your app, offering storage, transformation, and delivery of images effortlessly.
7. Ahoy: This gem helps you with analytics and tracking user visits in a Rails application, providing insights into user behavior.
8. Faker: Generate fake data for your application to use during testing and development, making your tests more robust.
9. Kaminari: An easy-to-use pagination solution for Rails, helping you to break up long lists into manageable pages.
10. Paperclip: A file attachment library for Active Record, making it straightforward to manage file uploads within your application.

When working with Ruby on Rails, developers often encounter a variety of common errors. Some of the most frequent issues include uninitialized constants, missing migrations, and undefined methods. These errors can halt the development process and lead to frustration. One way to address these problems is to carefully check your code for typos or incorrect references. For instance, if you see an 'uninitialized constant' error, ensuring that your class or module is properly defined and correctly named can often resolve the issue.

Another common error is the dreaded ActiveRecord::RecordNotFound, which occurs when a record you are attempting to access does not exist in the database. To fix this, you can use find_by instead of find, which returns nil rather than raising an exception if no record is found. Additionally, always ensure that you have run rails db:migrate to keep your database schema up-to-date, which can prevent migration-related errors from emerging.