Schema using default Entity Framework Code First conventions.

schema-before

CREATE TABLE [dbo].[Authors](
  [ID] [int] IDENTITY(1,1) NOT NULL,
	[Name] [nvarchar](max) NULL,
	[TwitterHandle] [nvarchar](max) NULL,
	[JobTitle_ID] [int] NULL,
 CONSTRAINT [PK_dbo.Authors] PRIMARY KEY CLUSTERED 
(
	[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

CREATE TABLE [dbo].[Categories](
	[ID] [int] IDENTITY(1,1) NOT NULL,
	[Name] [nvarchar](max) NULL,
 CONSTRAINT [PK_dbo.Categories] PRIMARY KEY CLUSTERED 
(
	[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

CREATE TABLE [dbo].[JobTitles](
	[ID] [int] IDENTITY(1,1) NOT NULL,
	[Title] [nvarchar](max) NULL,
 CONSTRAINT [PK_dbo.JobTitles] PRIMARY KEY CLUSTERED 
(
	[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

CREATE TABLE [dbo].[Posts](
	[ID] [int] IDENTITY(1,1) NOT NULL,
	[Title] [nvarchar](max) NULL,
	[Url] [nvarchar](max) NULL,
	[Author_ID] [int] NULL,
	[Category_ID] [int] NULL,
 CONSTRAINT [PK_dbo.Posts] PRIMARY KEY CLUSTERED 
(
	[ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]


ALTER TABLE [dbo].[Authors]  WITH CHECK ADD  CONSTRAINT [FK_dbo.Authors_dbo.JobTitles_JobTitle_ID] FOREIGN KEY([JobTitle_ID])
REFERENCES [dbo].[JobTitles] ([ID])

ALTER TABLE [dbo].[Authors] CHECK CONSTRAINT [FK_dbo.Authors_dbo.JobTitles_JobTitle_ID]

ALTER TABLE [dbo].[Posts]  WITH CHECK ADD  CONSTRAINT [FK_dbo.Posts_dbo.Authors_Author_ID] FOREIGN KEY([Author_ID])
REFERENCES [dbo].[Authors] ([ID])

ALTER TABLE [dbo].[Posts] CHECK CONSTRAINT [FK_dbo.Posts_dbo.Authors_Author_ID]

ALTER TABLE [dbo].[Posts]  WITH CHECK ADD  CONSTRAINT [FK_dbo.Posts_dbo.Categories_Category_ID] FOREIGN KEY([Category_ID])
REFERENCES [dbo].[Categories] ([ID])

ALTER TABLE [dbo].[Posts] CHECK CONSTRAINT [FK_dbo.Posts_dbo.Categories_Category_ID]